CN109219913B

CN109219913B - Charging system, charging method and power adapter

Info

Publication number: CN109219913B
Application number: CN201780016831.XA
Authority: CN
Inventors: 田晨; 张加亮
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2017-04-06
Filing date: 2017-04-06
Publication date: 2022-04-15
Anticipated expiration: 2037-04-06
Also published as: JP6743271B2; CN109219913A; EP3451488B1; US10910861B2; ES2770114T3; JP2019521637A; EP3451488A1; US20190260218A1; EP3451488A4; KR102249050B1; KR20190031309A; WO2018184178A1

Abstract

A charging system, a charging method, and a power adapter, wherein the power adapter (1) includes: the power adapter comprises a first rectifying unit (101), a switch unit (102), a transformer (103), a second rectifying unit (104), a first charging interface (105), a first current sampling circuit (1061), a first capacitor bank (115), a second capacitor bank (116) and a control unit (107), wherein the control unit outputs a control signal to the switch unit and judges the output current of the power adapter according to the current sampling value when the power adapter enters a first charging mode, and the control unit shields the first capacitor bank when the output current of the power adapter is at a rising edge or a falling edge; when the output current of the power adapter is in a platform section, the control unit enables the first capacitor bank to work. The power adapter can effectively reduce temperature rise, prolong service life, reduce volume and facilitate miniaturization design.

Description

Charging system, charging method and power adapter

Technical Field

The present invention relates to the field of terminal device technologies, and in particular, to a power adapter, a charging system, and a charging method for a terminal.

Background

Mobile terminals are typically charged through a power adapter. The secondary side of the power adapter is generally provided with a solid capacitor as an output capacitor for voltage stabilization and filtering, and the service life of the solid capacitor has a great relationship with the temperature rise in use.

In the related art, the primary side of the power adapter does not need to be provided with an electrolytic capacitor, and the mobile terminal can be subjected to high-power pulse charging. Because the primary side does not have the electrolytic capacitor, the output capacitor (solid-state capacitor) of the secondary side can release all energy when the input power supply of the power adapter is positioned in a wave trough, so that the power adapter is charged and discharged violently in a pulse period, and the larger the charging and discharging current is, the larger the current ripple is, the higher the temperature rise of the solid-state capacitor can be caused, and the service life of the solid-state capacitor is greatly influenced.

If the solid capacitor supports such a large charging and discharging current, the capacitance value of the fixed capacitor needs to be set to be large, so that a large space is occupied, and the miniaturization design of the power adapter is not facilitated; if the secondary side of the power adapter is not provided with the solid capacitor, the filtering effect of the power adapter is poorer when the power adapter charges the mobile terminal with high-power pulses, so that the switching ripple of the output signal is large, and the charging effect is influenced.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, a first objective of the present invention is to provide a power adapter, which can effectively reduce temperature rise, improve service life, reduce size, and facilitate miniaturization design.

A second object of the present invention is to provide a charging system. A third object of the present invention is to propose a charging method for a terminal.

In order to achieve the above object, a power adapter according to an embodiment of a first aspect of the present invention includes: a first rectifying unit for rectifying an input alternating current to output a voltage of a first ripple waveform; a switching unit for modulating a voltage of the first ripple waveform according to a control signal; a transformer for outputting a voltage of a second ripple waveform according to the modulated voltage of the first ripple waveform; a second rectifying unit for rectifying the voltage of the second ripple waveform to output a voltage of a third ripple waveform; a first current sampling circuit for current sampling an output of the second rectifying unit to obtain a current sample value; the first capacitor bank and the second capacitor bank are respectively connected to the output end of the second rectifying unit; the control unit is respectively connected with the first current sampling circuit and the switch unit, and is used for outputting the control signal to the switch unit and judging the output current of the power adapter according to the current sampling value when the power adapter enters a first charging mode, wherein when the output current of the power adapter is at a rising edge or a falling edge, the control unit shields the first capacitor bank; when the output current of the power adapter is in a platform section, the control unit enables the first capacitor bank to work.

According to the power adapter provided by the embodiment of the invention, the first capacitor bank and the second capacitor bank are arranged at the output end of the second rectifying unit, and the output of the second rectifying unit is subjected to current sampling through the first current sampling circuit, so that the output current of the power adapter is judged according to the current sampling value when the power adapter enters a first charging mode, wherein when the output current of the power adapter is at a rising edge or a falling edge, the control unit shields the first capacitor bank to prevent violent charging and discharging, the temperature rise can be effectively reduced, and the service life is prolonged; when power adapter's output current was in the platform section, the control unit enabled first electric capacity group and carried out work, and first electric capacity group and second electric capacity group carry out work simultaneously like this, promote the filtering effect greatly, ensure power adapter reliable and stable operation, improve the charging effect.

In order to achieve the above object, a charging system according to an embodiment of a second aspect of the present invention includes: a terminal; the power adapter is used for charging the terminal.

According to the charging system provided by the embodiment of the invention, the terminal is charged through the power adapter, so that when the output current of the power adapter is at the rising edge or the falling edge, the first capacitor bank is shielded to prevent severe charging and discharging, the temperature rise can be effectively reduced, and the service life is prolonged. And the first capacitor bank is only used for supporting the second charging mode with low power, so that a large capacitance value is not needed, the number and the volume of capacitors are reduced, the volume of the power adapter is saved, the power density and the product expressive force are improved, and the miniaturization design of the power adapter is facilitated.

In order to achieve the above object, a third embodiment of the present invention provides a charging method for a terminal, the terminal being charged by a power adapter, a first capacitor bank and a second capacitor bank being connected to a secondary side of the power adapter, the charging method including: performing primary rectification on input alternating current to output a voltage of a first ripple waveform; modulating the voltage of the first ripple waveform by controlling a switching unit in the power adapter, and outputting the voltage of a second ripple waveform by transformation of a transformer; performing secondary rectification on the voltage of the second ripple waveform to output a voltage of a third ripple waveform; carrying out current sampling on the output after secondary rectification to obtain a current sampling value, and judging the output current of the power adapter according to the current sampling value when the power adapter enters a first charging mode; when the output current of the power adapter is at a rising edge or a falling edge, shielding the first capacitor bank; and enabling the first capacitor bank to work when the output current of the power adapter is in the platform section.

According to the charging method for the terminal, the first capacitor bank and the second capacitor bank are arranged on the secondary side of the power adapter, and the current sampling value is obtained by carrying out current sampling on the output after secondary rectification, so that the output current of the power adapter is judged according to the current sampling value when the power adapter enters a first charging mode, wherein when the output current of the power adapter is at a rising edge or a falling edge, the first capacitor bank is shielded to prevent severe charging and discharging, so that the temperature rise can be effectively reduced, and the service life is prolonged; when power adapter's output current was located the platform section, made the work of first electric capacity group, first electric capacity group and second electric capacity group worked simultaneously like this, promoted the filtering effect greatly, ensured power adapter reliable and stable operation, improved the charging effect.

Drawings

Fig. 1A is a block diagram of a charging system for a terminal according to an embodiment of the present invention, which employs a flyback switching power supply;

fig. 1B is a block diagram of a charging system for a terminal using a forward switching power supply according to an embodiment of the present invention;

fig. 1C is a block schematic diagram of a charging system for a terminal employing a push-pull switching power supply according to one embodiment of the present invention;

fig. 1D is a block diagram of a charging system for terminals using a half-bridge switching power supply according to an embodiment of the present invention;

FIG. 1E is a block diagram of a charging system for terminals using a full-bridge switching power supply according to one embodiment of the present invention;

fig. 2A is a block diagram illustrating a charging system for a terminal according to an embodiment of the present invention;

FIG. 2B is a schematic circuit diagram of the secondary side of the power adapter in accordance with one embodiment of the present invention;

FIG. 2C is a waveform diagram of the output current of the power adapter and the switching signal of the selection switch according to one embodiment of the present invention;

FIG. 3 is a schematic diagram of a charging voltage waveform output by the power adapter to the battery according to one embodiment of the present invention;

FIG. 4A is a schematic diagram of a charging current waveform output to a battery by a power adapter according to one embodiment of the present invention;

FIGS. 4B and 4C are schematic diagrams of a pulsatile waveform of one embodiment of the present invention;

FIG. 4D is a schematic illustration of different pulsatile waveforms for one embodiment of the present invention;

FIG. 4E is a schematic illustration of different pulsing waveforms according to another embodiment of the present invention;

FIG. 4F is a schematic illustration of different pulsatile waveforms for yet another embodiment of the present invention;

FIG. 5 is a diagram illustrating control signals output to a switch unit according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a fast charge process according to one embodiment of the present invention;

fig. 7A is a block schematic diagram of a charging system for a terminal according to one embodiment of the invention;

FIG. 7B is a block diagram of a power adapter with an LC filter circuit according to one embodiment of the present invention;

fig. 8 is a block schematic diagram of a charging system for a terminal according to another embodiment of the present invention;

fig. 9 is a block schematic diagram of a charging system for a terminal according to yet another embodiment of the present invention;

fig. 10 is a block schematic diagram of a charging system for a terminal according to yet another embodiment of the present invention;

FIG. 11 is a block diagram of a sampling unit according to one embodiment of the present invention;

fig. 12 is a block schematic diagram of a charging system for a terminal according to yet another embodiment of the present invention;

fig. 13 is a block diagram of a terminal according to an embodiment of the present invention;

fig. 14 is a block schematic diagram of a terminal according to another embodiment of the present invention;

fig. 15 is a flowchart of a charging method for a terminal according to an embodiment of the present invention;

fig. 16 is a flowchart of a charging method for a terminal according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

First, the inventor of the present application found that, as the power of the power adapter becomes higher, when the power adapter charges the battery of the mobile terminal, the polarization resistance of the battery becomes higher and the temperature of the battery is raised, thereby reducing the service life of the battery and affecting the reliability and safety of the battery.

Moreover, most of the devices cannot directly work by using alternating current when the alternating current power supply is used for supplying power, because the alternating current, such as 220V commercial power of 50Hz, outputs electric energy intermittently, and an electrolytic capacitor is required to store energy so as not to be interrupted, so that when the power supply is in a wave valley, the power supply continuously depends on the energy stored by the electrolytic capacitor to maintain stable power supply. Therefore, when the mobile terminal is charged by the ac power source through the power adapter, the ac power supplied by the ac power source, for example, 220V ac power, is converted into a stable dc power to be supplied to the mobile terminal. However, the power adapter charges the battery of the mobile terminal, so that the mobile terminal is indirectly supplied with power, and the continuity of power supply is ensured by the battery, so that the power adapter does not need to continuously output stable direct current when charging the battery.

Therefore, the primary side of the power adapter does not need to be provided with an electrolytic capacitor, and the mobile terminal can be subjected to high-power pulse charging, namely, the mobile terminal works in a first charging mode, and meanwhile, the power adapter can also support a second charging mode to work.

Before describing the charging system, the power adapter, and the charging method for the terminal according to the embodiments of the present invention, a power adapter that waits for a charging device to be charged in the terminal in the related art will be described, which may be referred to as a "related adapter" below.

When the relevant adapter works in the constant voltage mode, the voltage output by the adapter is kept constant basically, such as 5V, 9V, 12V or 20V.

The voltage output by the relevant adapter is not suitable for being directly applied to both ends of the battery, but needs to be converted by a conversion circuit in the device to be charged (such as a terminal) to obtain the charging voltage and/or charging current expected by the battery in the device to be charged (such as the terminal).

The conversion circuit is used for converting the voltage output by the relevant adapter so as to meet the requirement of the charging voltage and/or the charging current expected by the battery.

As an example, the conversion circuit may refer to a charging management module, such as a charging IC in a terminal, for managing a charging voltage and/or a charging current of a battery during charging of the battery. The conversion circuit has the function of a voltage feedback module and/or the function of a current feedback module so as to realize the management of the charging voltage and/or the charging current of the battery.

For example, the charging process of the battery may include one or more of a trickle charge phase, a constant current charge phase, and a constant voltage charge phase. During the trickle charge phase, the conversion circuit may utilize a current feedback loop such that the current entering the battery during the trickle charge phase satisfies an expected charge current level (e.g., a first charge current) of the battery. During the constant current charging phase, the inverter circuit may utilize a current feedback loop such that the current entering the battery during the constant current charging phase satisfies a desired charging current level of the battery (e.g., a second charging current, which may be greater than the first charging current). In the constant voltage charging stage, the conversion circuit can utilize a voltage feedback loop to enable the voltage loaded across the battery in the constant voltage charging stage to meet the expected charging voltage of the battery.

As an example, when the voltage output by the relevant adapter is greater than the expected charging voltage of the battery, the converting circuit may be configured to perform a voltage-down conversion process on the voltage output by the relevant adapter, so that the charging voltage obtained after the voltage-down conversion meets the expected charging voltage requirement of the battery. As another example, when the voltage output by the relevant adapter is smaller than the expected charging voltage of the battery, the converting circuit may be configured to perform a voltage-up conversion process on the voltage output by the relevant adapter, so that the charging voltage obtained after the voltage-up conversion meets the expected charging voltage requirement of the battery.

As another example, taking the output of 5V constant voltage by the relevant adapter as an example, when the battery includes a single battery cell (taking a lithium battery cell as an example, the charge cut-off voltage of the single battery cell is 4.2V), the converting circuit (for example, a Buck step-down circuit) may perform a step-down conversion process on the voltage output by the relevant adapter, so that the charge voltage obtained after the step-down process meets the charge voltage requirement expected by the battery.

As another example, taking the example that the relevant adapter outputs a constant voltage of 5V, when the relevant adapter is charged by a battery having two or more single cells connected in series (taking a lithium battery cell as an example, the charge cut-off voltage of a single cell is 4.2V), the conversion circuit (for example, a Boost circuit) may perform a Boost conversion process on the voltage output by the relevant adapter, so that the boosted charging voltage meets the charge voltage requirement expected by the battery.

The conversion circuit is limited by the reason that the conversion efficiency of the circuit is low, so that the electric energy of the part which is not converted is dissipated in a heat form, the heat can be focused inside the equipment to be charged (such as a terminal), the design space and the heat dissipation space of the equipment to be charged (such as the terminal) are small (for example, the physical size of a mobile terminal used by a user is increasingly light and thin, and meanwhile, a large number of electronic components are densely distributed in the mobile terminal to improve the performance of the mobile terminal), so that not only is the design difficulty of the conversion circuit improved, but also the heat focused in the equipment to be charged (such as the terminal) is difficult to dissipate in time, and further the abnormality of the equipment to be charged (such as the terminal) can be caused.

For example, heat accumulated in the converter circuit may cause thermal interference to electronic components near the converter circuit, which may cause abnormal operation of the electronic components; and/or, for example, heat build-up on the converter circuit may shorten the useful life of the converter circuit and nearby electronic components; and/or, for example, the heat accumulated on the conversion circuit may cause thermal interference to the battery, thereby causing abnormal charging and discharging of the battery; and/or, for example, heat accumulated on the conversion circuit may cause the temperature of the device to be charged (e.g., the terminal) to increase, which may affect the user experience during charging; and/or, for example, heat accumulated on the conversion circuit may cause a short circuit of the conversion circuit itself, so that the voltage output by the relevant adapter is directly applied to two ends of the battery to cause charging abnormality, and when the battery is in an overvoltage charging condition for a long time, explosion of the battery may even be caused, which has a certain potential safety hazard.

The power adapter provided by the embodiment of the invention can obtain the state information of the battery, the state information of the battery at least comprises the current electric quantity information and/or voltage information of the battery, the power adapter adjusts the output voltage of the power adapter according to the obtained state information of the battery so as to meet the requirement of the expected charging voltage and/or charging current of the battery, the voltage output by the power adapter after adjustment can be directly loaded to two ends of the battery to charge the battery, and the voltage output by the power adapter is the voltage with a pulsating waveform.

The power adapter has the functions of a voltage feedback module and a current feedback module so as to realize the management of the charging voltage and/or the charging current of the battery.

The power adapter adjusting its own output voltage according to the acquired state information of the battery may refer to: the power adapter can acquire the state information of the battery in real time, and adjust the voltage output by the power adapter according to the acquired real-time state information of the battery each time so as to meet the expected charging voltage and/or charging current of the battery.

The power adapter adjusting its own output voltage according to the state information of the battery acquired in real time may refer to: along with the continuous rising of the charging voltage of the battery in the charging process, the power adapter can acquire the current state information of the battery at different moments in the charging process, and adjust the output voltage of the power adapter in real time according to the current state information of the battery so as to meet the requirement of the expected charging voltage and/or charging current of the battery, and the voltage output by the power adapter after adjustment can be directly loaded to the two ends of the battery to charge the battery.

For example, the charging process of the battery may include one or more of a trickle charge phase, a constant current charge phase, and a constant voltage charge phase. In the trickle-charging stage, the power adapter may output a first charging current to charge the battery in the trickle-charging stage to meet the expected charging current requirement of the battery (the first charging current may be a current with a pulsating waveform). During the constant-current charging phase, the power adapter may utilize a current feedback loop such that the current output by the power adapter and entering the battery during the constant-current charging phase meets the desired charging current requirement of the battery (e.g., a second charging current, which may be larger than the first charging current, and may be a current peak value of a ripple waveform during the constant-current charging phase larger than a current peak value of a ripple waveform during the trickle charging phase, and a constant current during the constant-current charging phase may mean that the current peak value or average value of the ripple waveform remains substantially constant). During the constant voltage charging phase, the power adapter may utilize a voltage feedback loop to keep the voltage (i.e., the voltage of the ripple waveform) output by the power adapter to the device to be charged (e.g., the terminal) constant during the constant voltage charging phase.

For example, the power adapter mentioned in the embodiments of the present invention may be mainly used for controlling a constant current charging phase of a battery in a device to be charged (e.g., a terminal). In other embodiments, the control functions of the trickle charge phase and the constant voltage charge phase of the battery in the device to be charged (e.g. the terminal) can also be cooperatively completed by the power adapter and the additional charging chip in the device to be charged (e.g. the terminal) mentioned in the embodiments of the present invention; compared with the constant-current charging stage, the charging power received by the battery in the trickle charging stage and the constant-voltage charging stage is smaller, and the efficiency conversion loss and the heat accumulation of the charging chip inside the device to be charged (such as a terminal) are acceptable. It should be noted that the constant-current charging phase or the constant-current phase mentioned in the embodiment of the present invention may refer to a charging mode for controlling the output current of the power adapter, and does not require that the output current of the power adapter is kept completely constant, for example, it may generally refer to that a current peak value or an average value of a ripple waveform output by the power adapter is kept substantially constant, or that a time period is kept substantially constant. For example, in practice, the power adapter is usually charged in a segmented constant current manner during the constant current charging phase.

The Multi-stage constant current charging (Multi-stage constant current charging) may have N constant current stages (N is an integer not less than 2), the Multi-stage constant current charging starts the first-stage charging with a predetermined charging current, the N constant current stages of the Multi-stage constant current charging are sequentially executed from the first stage to the (N-1) th stage, and when a previous constant current stage in the constant current stages is shifted to a next constant current stage, a current peak value or an average value of a ripple waveform may become small; when the battery voltage reaches the charging termination voltage threshold, the previous constant current stage in the constant current stages will shift to the next constant current stage. The current conversion process between two adjacent constant current stages can be gradual change, or can also be step-type jump change.

Further, it should be noted that a "terminal" as used in embodiments of the present invention may include, but is not limited to, a device configured to receive/transmit communication signals via a wireline connection (e.g., via a Public Switched Telephone Network (PSTN), a Digital Subscriber Line (DSL), a digital cable, a direct cable connection, and/or another data connection/network) and/or via a wireless interface (e.g., for a cellular network, a Wireless Local Area Network (WLAN), a digital television network such as a DVB-H network, a satellite network, an AM-FM broadcast transmitter, and/or another communication terminal). Terminals that are arranged to communicate over a wireless interface may be referred to as "wireless communication terminals", "wireless terminals", and/or "mobile terminals". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; a Personal Communications System (PCS) terminal that may combine a cellular radiotelephone with data processing, facsimile and data communications capabilities; PDAs that may include radiotelephones, pagers, internet/intranet access, Web browsers, notepads, calendars, and/or Global Positioning System (GPS) receivers; and conventional laptop and/or palmtop receivers or other electronic devices that include a radiotelephone transceiver.

In addition, in the embodiment of the present invention, when the voltage of the ripple waveform output by the power adapter is directly applied to the battery of the terminal to charge the battery, the charging current is characterized in the form of ripple waves such as steamed bread waves and trapezoidal waves, it can be understood that the charging current charges the battery in an intermittent manner, and the period of the charging current varies with the frequency of the input alternating current such as the alternating current grid, for example, the period of the charging current corresponds to a frequency which is an integral multiple or an inverse multiple of the grid frequency. And, when the charging current charges the battery in an intermittent manner, the current waveform corresponding to the charging current may be one or a set of pulses synchronized with the grid.

A charging system and a power adapter, a charging method for a terminal, proposed according to an embodiment of the present invention are described below with reference to the accompanying drawings.

As shown in fig. 1A to 14, the charging system according to the embodiment of the present invention includes a power adapter 1 and a terminal 2.

As shown in fig. 2A and 2B, the power adapter 1 includes: the circuit comprises a first rectifying unit 101, a switching unit 102, a transformer 103, a second rectifying unit 104, a first current sampling circuit 1061, a first capacitor bank 115, a second capacitor bank 116 and a control unit 107. The first rectifying unit 101 rectifies an input alternating current (commercial power, for example, AC220V) to output a voltage of a first pulsating waveform, for example, a steamed bread wave voltage, wherein, as shown in fig. 1A, the first rectifying unit 101 may be a full bridge rectifying circuit configured by four diodes. The switch unit 102 is configured to modulate the voltage of the first Pulse waveform according to the control signal, wherein the switch unit 102 may be formed by a MOS transistor, and performs a PWM (Pulse Width Modulation) control on the MOS transistor to perform a chopper Modulation on the steamed bun wave voltage. The transformer 103 is configured to output a voltage of a second ripple waveform according to the modulated voltage of the first ripple waveform, and the second rectifying unit 104 is configured to rectify the voltage of the second ripple waveform to output a voltage of a third ripple waveform, where the second rectifying unit 104 may be composed of a diode or an MOS transistor, and is capable of implementing secondary synchronous rectification, so that the third ripple waveform is synchronized with the modulated first ripple waveform, and it should be noted that the third ripple waveform is synchronized with the modulated first ripple waveform, specifically, a phase of the third ripple waveform is consistent with a phase of the modulated first ripple waveform, and an amplitude of the third ripple waveform is consistent with an amplitude variation trend of the modulated first ripple waveform. The first current sampling circuit 1061 is configured to sample a current output by the second rectifying unit 104 to obtain a current sample value, the first capacitor bank 115 and the second capacitor bank 116 are respectively connected to an output end of the second rectifying unit 104, the control unit 107 is respectively connected to the first current sampling circuit 1061 and the switching unit 102, the control unit 107 is configured to output a control signal to the switching unit 102, and determine an output current of the power adapter according to the current sample value when the power adapter enters a first charging mode, where when the output current of the power adapter is at a rising edge or a falling edge, the control unit 107 shields the first capacitor bank 115 to prevent the first capacitor bank 115 from being charged and discharged violently; when the output current of the power adapter is in the platform section, the control unit 107 enables the first capacitor bank 115 to operate, so that the first capacitor bank 115 and the second capacitor bank 116 perform the filtering operation simultaneously.

The output current waveform of the power adapter can be adjusted by controlling the power adapter, so that the current waveform of the power adapter is a waveform similar to a trapezoidal wave, as shown in fig. 2C. In the embodiment of the present invention, the output current of the power adapter is in a platform section, specifically, the output current waveform of the power adapter is in a stable and unchangeable stage of a trapezoidal wave.

When the output current of the power adapter is in the platform section, the first capacitor bank 115 is connected into the circuit, the first capacitor bank cannot sense external AC frequency ripples at the moment, and the absorbed high-frequency switch ripples are all high-frequency switch ripples, so that the temperature rise of the first capacitor bank 115 cannot be guaranteed to be too high, and the filtering effect can be improved.

According to one embodiment of the present invention, as shown in fig. 2B, the first capacitor bank 115 includes a plurality of solid state capacitors C01 connected in parallel, and the second capacitor bank 116 includes a plurality of ceramic capacitors C02 connected in parallel.

As shown in fig. 2B, the power adapter further includes a selection switch 117, one end of the selection switch 117 is connected to one end of the first capacitor bank 115, the other end of the selection switch 117 is grounded, a control end of the selection switch 117 is connected to the control unit 107, and the other end of the first capacitor bank 115 is connected to the output end of the second rectifying unit 104.

Thus, when the output current of the power adapter is at a rising edge or a falling edge, the control unit 107 controls the selection switch 117 to be turned off, so that the first capacitor bank 115 cuts off the circuit; when the output current of the power adapter is in the platform section, the control unit 107 controls the selection switch 117 to be closed, so that the first capacitor bank 115 is switched into the circuit.

According to an embodiment of the present invention, as shown in fig. 2B, the selection switch 117 may be a MOS transistor.

That is, when the power adapter enters the first charging mode, i.e., the quick charging mode, the control unit 107 controls the selection switch 117, e.g., MOSFET. When the output current of the power adapter is at a rising edge or a falling edge, the MOSFET is closed, the cathode of the solid capacitor of the first capacitor bank is disconnected with the ground GND, the solid capacitor is shielded, and the ceramic capacitor of the second capacitor bank plays a role in filtering; when the output current of the power adapter is in the platform section, the MOSFET is turned on, so that the solid capacitor of the first capacitor bank is connected into the circuit, and the filtering operation is also carried out.

The waveform of the switching signal of the MOSFET and the waveform of the output current of the power adapter are shown in fig. 2C, and the MOSFET is turned on at a high level and turned off at a low level.

In an embodiment of the present invention, when the power adapter enters a second charging mode, the control unit 107 enables the first capacitor set 115 to operate, wherein the charging speed of the first charging mode is greater than the charging speed of the second charging mode.

That is, when the power adapter enters the second charging mode, i.e., the normal charging mode, the control unit 107 controls the selection switch 117, e.g., the MOSFET, to turn on the MOSFET, and connects the cathode of the solid capacitor of the first capacitor bank to the ground GND, so that the solid capacitor can operate, and at this time, the solid capacitor of the first capacitor bank and the ceramic capacitor of the second capacitor bank operate simultaneously, so as to provide a low-power 5V output, and the solid capacitor mainly provides the output power when the input voltage of the power adapter is at the valley.

Therefore, in order to enable the power adapter to output direct current 5V in the second charging mode and to be loaded, the solid-state capacitor of the first capacitor bank cannot be completely removed, and the power adapter of the embodiment of the invention adopts a MOSFET to enable the solid-state capacitor, so that the solid-state capacitor is in a working state in the first charging mode; after the power adapter enters the first charging mode, the solid capacitor is shielded when the output current of the power adapter is at the rising edge and the falling edge, so that severe charging and discharging of the solid capacitor are prevented, and the temperature rise of the solid capacitor is not too high.

In summary, in the embodiment of the present invention, the solid capacitor sensitive to temperature rise does not need to be charged or discharged acutely in the first charging mode, so that the temperature rise can be effectively reduced, and the service life can be prolonged. And the solid-state capacitor is only used for supporting the second charging mode with low power, so that a large capacitance value is not needed, the number and the volume of the capacitor are reduced, the volume of the power adapter is reduced, the power density and the product expressive force can be improved, and the miniaturization design of the power adapter is facilitated.

In one embodiment of the present invention, as shown in fig. 1A, the power adapter 1 may employ a flyback switching power supply. Specifically, the transformer 103 includes a primary winding and a secondary winding, one end of the primary winding is connected to the first output terminal of the first rectifying unit 101, the second output terminal of the first rectifying unit 101 is grounded, the other end of the primary winding is connected to the switching unit 102 (for example, the switching unit 102 is a MOS transistor, and it means that the other end of the primary winding is connected to a drain of the MOS transistor), and the transformer 103 is configured to output a voltage of the second ripple waveform according to the modulated voltage of the first ripple waveform.

The transformer 103 is a high-frequency transformer, the operating frequency of which may be 50KHz-2MHz, and the high-frequency transformer couples the modulated voltage of the first ripple waveform to the secondary winding, and outputs the voltage from the secondary winding. In the embodiment of the present invention, a high-frequency transformer is adopted, and the characteristic that the high-frequency transformer has a smaller volume than a low-frequency transformer (a low-frequency transformer is also called a power frequency transformer, and is mainly used for the frequency of the commercial power, for example, 50Hz or 60Hz alternating current) can be utilized, so that the power adapter 1 can be miniaturized.

According to an embodiment of the present invention, as shown in fig. 1B, the power adapter 1 may further employ a forward switching power supply. Specifically, the transformer 103 includes a first winding, a second winding, and a third winding, wherein a dotted terminal of the first winding is connected to the second output terminal of the first rectifying unit 101 through a reverse diode, a dotted terminal of the first winding is connected to the dotted terminal of the second winding and then connected to the first output terminal of the first rectifying unit 101, a dotted terminal of the second winding is connected to the switching unit 102, and the third winding is connected to the second rectifying unit 104. The reverse diode plays a role in reverse peak clipping, the induced electromotive force generated by the first winding can clip the amplitude of the reverse electromotive force through the reverse diode, the amplitude clipping energy is returned to the output of the first rectifying unit, the output of the first rectifying unit is charged, and the magnetic field generated by the current flowing through the first winding can demagnetize the iron core of the transformer, so that the magnetic field intensity in the iron core of the transformer is restored to the initial state. The transformer 103 is configured to output a voltage of a second ripple waveform according to the modulated voltage of the first ripple waveform.

According to an embodiment of the present invention, as shown in fig. 1C, the power adapter 1 may also employ a push-pull switching power supply. Specifically, the transformer comprises a first winding, a second winding, a third winding and a fourth winding, wherein the homonymous end of the first winding is connected with the switch unit, the synonym end of the first winding is connected with the homonymous end of the second winding and then connected with the first output end of the first rectifying unit, the synonym end of the second winding is connected with the switch unit, the synonym end of the third winding is connected with the homonymous end of the fourth winding, and the transformer is used for outputting the voltage of the second pulse waveform according to the modulated voltage of the first pulse waveform.

As shown in fig. 1C, the switching unit 102 includes a first MOS transistor Q1 and a second MOS transistor Q2, the transformer 103 includes a first winding, a second winding, a third winding and a fourth winding, a dotted terminal of the first winding is connected to the drain of the first MOS transistor Q1 in the switching unit 102, a dotted terminal of the first winding is connected to the dotted terminal of the second winding, a node between the dotted terminal of the first winding and the dotted terminal of the second winding is connected to the first output terminal of the first rectifying unit 101, a dotted terminal of the second winding is connected to the drain of the second MOS transistor Q2 in the switching unit 102, a source of the first MOS transistor Q1 is connected to the source of the second MOS transistor Q2 and then connected to the second output terminal of the first rectifying unit 101, a dotted terminal of the third winding is connected to the first input terminal of the second rectifying unit 104, a dotted terminal of the third winding is connected to the dotted terminal of the fourth winding, and a node between the dotted terminal of the third winding and the fourth winding is grounded, the synonym terminal of the fourth winding is connected to the second input terminal of the second rectifying unit 104.

As shown in fig. 1C, a first input terminal of the second rectifying unit 104 is connected to the dotted terminal of the third winding, a second input terminal of the second rectifying unit 104 is connected to the dotted terminal of the fourth winding, and the second rectifying unit 104 is configured to rectify the voltage of the second ripple waveform to output a voltage of a third ripple waveform. The second rectifying unit 104 may include two diodes, one diode having an anode connected to the dotted terminal of the third winding, the other diode having an anode connected to the dotted terminal of the fourth winding, and cathodes connected together.

According to an embodiment of the present invention, as shown in fig. 1D, the power adapter 1 may also employ a half-bridge switching power supply. Specifically, the switching unit 102 includes a first MOS transistor Q1, a second MOS transistor Q2, a first capacitor C1, and a second capacitor C2, the first capacitor C1 is connected in series with the second capacitor C2 and then connected in parallel to the output end of the first rectifying unit 101, the first MOS transistor Q1 is connected in series with the second MOS transistor Q2 and then connected in parallel to the output end of the first rectifying unit 101, the transformer 103 includes a first winding, a second winding, and a third winding, the dotted end of the first winding is connected to a node between the first capacitor C1 and the second capacitor C2 connected in series, the dotted end of the first winding is connected to a node between the first MOS transistor Q1 and the second MOS transistor Q2 connected in series, the dotted end of the second winding is connected to a first input end of the second rectifying unit 104, the dotted end of the second winding is connected to a dotted end of the third winding and then connected to the ground, and the dotted end of the third winding is connected to a second input end of the second rectifying unit 104. The transformer 103 is configured to output a voltage of a second ripple waveform according to the modulated voltage of the first ripple waveform.

According to an embodiment of the present invention, as shown in fig. 1E, the power adapter 1 may also employ a full-bridge switching power supply. Specifically, the switching unit 102 includes a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3, and a fourth MOS transistor Q4, the third MOS transistor Q3 and the fourth MOS transistor Q4 are connected in series and then connected in parallel to the output end of the first rectifying unit 101, the first MOS transistor Q1 and the second MOS transistor Q2 are connected in series and then connected in parallel to the output end of the first rectifying unit 101, the transformer 103 includes a first winding, a second winding, and a third winding, the dotted terminal of the first winding is connected to a node between the third MOS transistor Q3 and the fourth MOS transistor Q4 connected in series, the dotted terminal of the first winding is connected to a node between the first MOS transistor Q1 and the second MOS transistor Q2 connected in series, the dotted terminal of the second winding is connected to the first input end of the second rectifying unit 104, the dotted terminal of the second winding is connected to the dotted terminal of the third winding and then connected to the second input end of the second rectifying unit 104. The transformer 103 is configured to output a voltage of a second ripple waveform according to the modulated voltage of the first ripple waveform.

Therefore, in the embodiment of the present invention, the power adapter 1 may output the voltage of the pulsating waveform by using any one of a flyback switching power supply, a forward switching power supply, a push-pull switching power supply, a half-bridge switching power supply, and a full-bridge switching power supply.

Further, in an embodiment of the present invention, as shown in fig. 1A, a second rectifying unit 104 is connected to the secondary winding of the transformer 103, and the second rectifying unit 104 is configured to rectify the voltage of the second ripple waveform to output a voltage of a third ripple waveform. The second rectifying unit 104 may be formed by a diode, and implements secondary synchronous rectification, so that the third ripple waveform and the modulated first ripple waveform are kept synchronous, where it should be noted that the third ripple waveform and the modulated first ripple waveform are kept synchronous, specifically, a phase of the third ripple waveform and a phase of the modulated first ripple waveform are kept consistent, and an amplitude of the third ripple waveform and an amplitude variation trend of the modulated first ripple waveform are kept consistent.

As shown in fig. 1A, the power adapter further includes a first charging interface 105, the first charging interface 105 is connected to an output end of the second rectifying unit 104, the first charging interface includes a power line and a data line, the power line is used for charging a battery of the terminal, the data line is used for communicating with the terminal, and the control unit determines a charging mode by communicating with the terminal when the first charging interface is connected to the second charging interface of the terminal, where the charging mode includes a first charging mode and a second charging mode.

And when the power adapter enters the first charging mode, the power adapter loads the voltage of the third ripple waveform to the battery of the terminal through the second charging interface, wherein the second charging interface is connected with the battery.

As shown in fig. 1A, the sampling unit 106 may include a first current sampling circuit 1061 and a first voltage sampling circuit 1062, the sampling unit 106 is configured to sample the voltage and/or the current output by the second rectifying unit 104 to obtain a voltage sampling value and/or a current sampling value, the control unit 107 is respectively connected to the sampling unit 106 and the switching unit 102, and the control unit 107 outputs a control signal to the switching unit 102 and adjusts a duty ratio of the control signal according to the voltage sampling value and/or the current sampling value, so that the voltage of the third ripple waveform output by the second rectifying unit 104 meets the charging requirement.

As shown in fig. 1A, the terminal 2 includes a second charging interface 201 and a battery 202, and the second charging interface 201 is connected to the battery 202, wherein when the second charging interface 201 is connected to the first charging interface 105, the second charging interface 201 loads a voltage with a third ripple waveform to the battery 202, so as to charge the battery 202.

It should be noted that the voltage of the third ripple waveform satisfies the charging requirement, which means that the voltage and the current of the third ripple waveform need to satisfy the charging voltage and the charging current when the battery is charged. That is, the control unit 107 adjusts the duty ratio of a control signal, such as a PWM signal, according to the sampled voltage and/or current output by the power adapter, and adjusts the output of the second rectifying unit 104 in real time, so as to implement closed-loop adjustment control, so that the voltage of the third ripple waveform meets the charging requirement of the terminal 2, and ensure that the battery 202 is charged safely and reliably, specifically, the charging voltage waveform output to the battery 202 is adjusted by the duty ratio of the PWM signal as shown in fig. 3, and the charging current waveform output to the battery 202 is adjusted by the duty ratio of the PWM signal as shown in fig. 4A.

It is to be understood that, when adjusting the duty ratio of the PWM signal, the adjustment instruction may be generated based on the voltage sample value, the current sample value, or both the voltage sample value and the current sample value.

Therefore, in the embodiment of the present invention, the switching unit 102 is controlled to directly perform PWM chopping modulation on the rectified voltage of the first ripple waveform, i.e., the steamed bread wave voltage, and the rectified voltage is sent to the high frequency transformer, coupled from the primary side to the secondary side through the high frequency transformer, and then is synchronously rectified and reduced to the steamed bread wave voltage/current, which may also be a trapezoidal wave voltage/current, and is directly sent to the battery, so as to realize the rapid charging of the battery. The voltage amplitude of the steamed bun waves/trapezoidal waves can be adjusted through the duty ratio of the PWM signals, and the output of the power adapter meets the charging requirement of the battery. Therefore, the power adapter of the embodiment of the invention cancels the primary electrolytic capacitors and the secondary electrolytic capacitors, and directly charges the battery through the voltage of the steamed bread waves and the trapezoidal waves, thereby reducing the volume of the power adapter, realizing the miniaturization of the power adapter and greatly reducing the cost.

It is understood that the pulse waveform delivered to the battery for rapidly charging the battery may be a complete pulse waveform, or may be a trapezoidal waveform obtained after performing peak clipping on the complete pulse waveform, where the peak clipping may be to filter out a portion of the pulse waveform exceeding a certain threshold, so as to control the peak value of the pulse waveform. In the embodiment shown in fig. 4B, the pulsation waveform is a complete pulsation waveform, and in the embodiment shown in fig. 4C, the pulsation waveform is a pulsation waveform after a peak clipping process.

The embodiment of the present invention does not specifically limit the manner of limiting the peak value of the third pulsation waveform.

Alternatively, in some embodiments, the third ripple waveform may be a complete ripple waveform, for example, the peak value of the current of the third ripple waveform may be controlled at the current value corresponding to the current limiting point by modulation of the switching unit under the condition that the third ripple waveform is ensured to be complete.

Alternatively, in other embodiments, the third pulse waveform may be a pulse waveform obtained after a peak clipping process.

As shown in fig. 4D, the pulse waveform 2 is a complete pulse waveform, the pulse waveform 1 is a pulse waveform obtained after peak clipping, and the lithium deposition phenomenon of the battery can be reduced and the charging safety can be improved by using the current of the two pulse waveforms to charge the device to be charged (such as a terminal). However, the area enclosed by the ripple waveform 1 and the time axis is larger than the area enclosed by the ripple waveform 2 and the time axis (the sum of the area enclosed by the ripple waveform 2 and the time axis and the area of the shaded part is equal to the area enclosed by the ripple waveform 1 and the time axis), and the charging efficiency (or the speed) of the power adapter of the embodiment of the invention is proportional to the area enclosed by the ripple waveform and the time axis, the larger the area enclosed by the ripple waveform and the time axis is, the higher the charging efficiency is, therefore, the efficiency of charging the device to be charged (such as a terminal) by using the current of the ripple waveform 1 is larger than the efficiency of charging the device to be charged (such as a terminal) by using the current of the ripple waveform 1.

Therefore, in the embodiment of the invention, the peak clipping treatment is carried out on the pulse waveform, so that the peak value of the output current of the power adapter is equal to the corresponding current value of the current limiting point, and the charging efficiency can be improved.

Further, taking fig. 4E and 4F as an example, the pulsation waveform 3 and the pulsation waveform 4 in fig. 4E are pulsation waveforms before peak clipping processing, the peak value of the pulsation waveform 3 is smaller than the peak value of the pulsation waveform 4, and the pulsation waveform 3 'and the pulsation waveform 4' in fig. 4F are pulsation waveforms obtained by performing peak clipping processing on the pulsation waveform 3 and the pulsation waveform 4 in fig. 4E, respectively. In fig. 4F, the area enclosed by the ripple waveform 4 ' and the time axis is equal to the sum of the area enclosed by the ripple waveform 3 ' and the time axis and the area of the shaded portion, and the area enclosed by the ripple waveform 4 ' and the time axis is larger than the area enclosed by the ripple waveform 3 ' and the time axis, so that the efficiency of charging the device to be charged (such as the terminal) by using the current of the ripple waveform 4 ' is higher.

That is, the higher the peak value of the ripple waveform before the peak clipping processing is performed, the higher the efficiency of charging with the current of the ripple waveform obtained after the peak clipping processing is finally performed. Therefore, the charging efficiency can be improved by increasing the peak value of the ripple waveform before the peak clipping process.

The peak value of the ripple waveform can be increased in various ways, for example, by selecting a PWM controller with a high maximum duty ratio, or by increasing the inductance of the transformer.

In a specific example of the present invention, the control Unit 107 may be an MCU (Micro Controller Unit), that is, a microprocessor integrated with a switch driving control function, a synchronous rectification function, and a voltage and current regulation control function.

According to an embodiment of the present invention, the control unit 107 is further configured to adjust the frequency of the control signal according to the voltage sampling value and/or the current sampling value, that is, the PWM signal output to the switching unit 102 is controlled to be output for a period of time and then to be stopped, and the output of the PWM signal is turned on again after the predetermined time is stopped, so that the voltage applied to the battery is intermittent, and the intermittent charging of the battery is realized, thereby avoiding a potential safety hazard caused by serious heat generation during the continuous charging of the battery, and improving the reliability and the safety of the charging of the battery.

For a lithium battery, under a low temperature condition, due to the reduction of the ionic and electronic conductivity of the lithium battery, the polarization degree is easily aggravated in the charging process, the polarization performance is more and more obvious by a continuous charging mode, and the possibility of lithium precipitation is increased, so that the safety performance of the battery is influenced. Moreover, continuous charging can cause continuous accumulation of heat due to charging, which causes continuous rise of the internal temperature of the battery, and when the temperature exceeds a certain limit value, the performance of the battery is limited, and meanwhile, potential safety hazards are increased.

In the embodiment of the invention, the frequency of the control signal is adjusted, so that the power adapter outputs intermittently, namely, a battery standing process is introduced in the battery charging process, the phenomenon of lithium precipitation possibly caused by polarization in continuous charging can be relieved, the influence of continuous accumulation of generated heat is weakened, the effect of temperature reduction is achieved, and the reliability and safety of battery charging are ensured.

As shown in fig. 5, the control signal output to the switching unit 102 may output the PWM signal for a period of time, then stop outputting for a period of time, and output the PWM signal for a period of time, so that the control signal output to the switching unit 102 is intermittent and has an adjustable frequency.

As shown in fig. 1A, the control unit 107 is connected to the first charging interface 105, and the control unit 107 is further configured to communicate with the terminal 2 through the first charging interface 105 to obtain the status information of the terminal 2. In this way, the control unit 107 is also configured to adjust the duty cycle of the control signal, e.g. the PWM signal, based on the state information of the terminal, the voltage sample value and/or the current sample value.

The state information of the terminal may include the power of the battery, the temperature of the battery, the voltage of the battery, interface information of the terminal, information of the path impedance of the terminal, and the like.

Specifically, first charging interface 105 includes: the battery charging system comprises a power line and a data line, wherein the power line is used for charging a battery, and the data line is used for communicating with a terminal. When the second charging interface 201 is connected to the first charging interface 105, the power adapter 1 and the terminal 2 may send a communication inquiry command to each other, and after receiving a corresponding response command, the power adapter 1 and the terminal 2 establish a communication connection, and the control unit 107 may acquire state information of the terminal 2, negotiate a charging mode and charging parameters (such as charging current and charging voltage) with the terminal 2, and control a charging process.

The charging modes supported by the power adapter and/or the terminal may include a second charging mode and a first charging mode. The charging speed of the first charging mode is greater than the charging speed of the second charging mode (e.g., the charging current of the first charging mode is greater than the charging current of the second charging mode). In general, the second charging mode can be understood as a charging mode in which the rated output voltage is 5V and the rated output current is 2.5A or less, and in addition, in the second charging mode, D + and D-in the output port data line of the power adapter can be short-circuited. The first charging mode in the embodiment of the present invention is different, and the power adapter in the first charging mode in the embodiment of the present invention may communicate with the terminal by using D + and D-in the data line to implement data exchange, that is, the power adapter and the terminal may send a fast charging instruction to each other: the power adapter sends a quick charging inquiry instruction to the terminal, after receiving a quick charging response instruction of the terminal, the power adapter acquires state information of the terminal according to the response instruction of the terminal, and the first charging mode is started, wherein the charging current in the first charging mode can be larger than 2.5A, for example, can reach 4.5A, or even larger. However, the second charging mode is not particularly limited in the embodiment of the present invention, and as long as the power adapter supports two charging modes, where the charging speed (or current) of one charging mode is greater than that of the other charging mode, the charging mode with the slower charging speed may be understood as the second charging mode. The charging power in the first charging mode may be 15W or more with respect to the charging power.

That is, control unit 107 communicates with terminal 2 through first charging interface 105 to determine a charging mode, where the charging mode includes a first charging mode and a second charging mode.

Specifically, the power adapter is connected to the terminal through a Universal Serial Bus (USB) interface, which may be a normal USB interface, a micro USB interface, or another type of USB interface. The data line in the USB interface, that is, the data line in the first charging interface, is used for bidirectional communication between the power adapter and the terminal, where the data line may be a D + line and/or a D-line in the USB interface, and the bidirectional communication may refer to information interaction between the power adapter and the terminal.

The power adapter is in bidirectional communication with the terminal through a data line in the USB interface so as to determine to use the first charging mode to charge the terminal.

It should be noted that, in the process that the power adapter negotiates with the terminal whether to adopt the first charging mode to charge the terminal, the power adapter may only maintain a connection state with the terminal, and does not charge the terminal, may also adopt the second charging mode to charge the terminal, and may also adopt a small current to charge the terminal, which is not specifically limited in this embodiment of the present invention.

And the power adapter adjusts the charging current to the charging current corresponding to the first charging mode to charge the terminal. After the power adapter determines to charge the terminal in the first charging mode, the power adapter may directly adjust the charging current to the charging current corresponding to the first charging mode, or may negotiate the charging current of the first charging mode with the terminal, for example, determine the charging current corresponding to the first charging mode according to the current electric quantity of the battery in the terminal.

In the embodiment of the invention, the power adapter does not increase the output current blindly to perform quick charging, but needs to perform bidirectional communication with the terminal to negotiate whether the first charging mode can be adopted or not, and compared with the prior art, the safety of the quick charging process is improved.

Optionally, as an embodiment, when the control unit 107 performs bidirectional communication with the terminal through a data line in the first charging interface to determine to charge the terminal using the first charging mode, the control unit sends a first instruction to the terminal, where the first instruction is used to inquire whether the terminal turns on the first charging mode; the control unit receives a reply instruction of the first instruction from the terminal, wherein the reply instruction of the first instruction is used for indicating that the terminal agrees to start the first charging mode.

Optionally, as an embodiment, before the control unit sends the first instruction to the terminal, the power adapter and the terminal are charged through the second charging mode, and after the control unit determines that the charging duration of the second charging mode is greater than a preset threshold, the control unit sends the first instruction to the terminal.

It should be understood that, after the power adapter determines that the charging duration of the second charging mode is greater than the preset threshold, the power adapter may regard that the terminal has identified itself as the power adapter, and may start the fast charging inquiry communication.

Optionally, as an embodiment, after determining that the charging current greater than or equal to the preset current threshold is used for charging for the preset time period, the power adapter sends the first instruction to the terminal.

Optionally, as an embodiment, the control unit is further configured to control the switch unit to control the power adapter to adjust the charging current to the charging current corresponding to the first charging mode, and before the power adapter charges the terminal with the charging current corresponding to the first charging mode, the control unit performs bidirectional communication with the terminal through a data line in the first charging interface to determine the charging voltage corresponding to the first charging mode, and controls the power adapter to adjust the charging voltage to the charging voltage corresponding to the first charging mode.

Optionally, as an embodiment, when the control unit performs bidirectional communication with the terminal through a data line in the first charging interface to determine the charging voltage corresponding to the first charging mode, the control unit sends a second instruction to the terminal, where the second instruction is used to inquire whether the current output voltage of the power adapter is suitable as the charging voltage of the first charging mode; the control unit receives a reply instruction of the second instruction sent by the terminal, wherein the reply instruction of the second instruction is used for indicating that the current output voltage of the power adapter is proper, higher or lower; and the control unit determines the charging voltage of the first charging mode according to a reply instruction of the second instruction.

Optionally, as an embodiment, before controlling the power adapter to adjust the charging current to the charging current corresponding to the first charging mode, the control unit further performs bidirectional communication with the terminal through a data line in the first charging interface to determine the charging current corresponding to the first charging mode.

Optionally, as an embodiment, when the control unit performs bidirectional communication with the terminal through a data line in the first charging interface to determine the charging current corresponding to the first charging mode, the control unit sends a third instruction to the terminal, where the third instruction is used to inquire about a maximum charging current currently supported by the terminal; the control unit receives a reply instruction of the third instruction sent by the terminal, wherein the reply instruction of the third instruction is used for indicating the maximum charging current currently supported by the terminal; and the control unit determines the charging current of the first charging mode according to a reply instruction of the third instruction.

The power adapter may directly determine the above-described maximum charging current as the charging current of the first charging mode, or set the charging current to a certain current value smaller than the maximum charging current.

Optionally, as an embodiment, in a process that the power adapter charges the terminal using the first charging mode, the control unit further performs bidirectional communication with the terminal through a data line in the first charging interface, so as to continuously adjust the charging current output by the power adapter to the battery by controlling the switch unit.

The power adapter may continuously query the current state information of the terminal, such as the battery voltage, battery level, etc., of the terminal, thereby continuously adjusting the charging current output by the power adapter to the battery.

Optionally, as an embodiment, the control unit performs bidirectional communication with the terminal through a data line in the first charging interface, so that when the switching unit is controlled to continuously adjust the charging current output by the power adapter to the battery, the control unit sends a fourth instruction to the terminal, where the fourth instruction is used to inquire about the current voltage of the battery in the terminal; the control unit receives a reply instruction of the fourth instruction sent by the terminal, wherein the reply instruction of the fourth instruction is used for indicating the current voltage of a battery in the terminal; the control unit adjusts the charging current output to the battery by the power adapter by controlling the switch unit according to the current voltage of the battery.

Optionally, as an embodiment, the control unit adjusts the charging current output from the power adapter to the battery to a charging current value corresponding to the current voltage of the battery by controlling the switch unit according to the current voltage of the battery and a preset corresponding relationship between a voltage value of the battery and a charging current value.

Specifically, the power adapter may store a corresponding relationship between a battery voltage value and a charging current value in advance, and the power adapter may also perform bidirectional communication with the terminal through a data line in the first charging interface, so as to obtain the corresponding relationship between the battery voltage value and the charging current value stored in the terminal from the terminal side.

Optionally, as an embodiment, in a process that the power adapter charges the terminal using the first charging mode, the control unit further performs bidirectional communication with the terminal through a data line in the first charging interface to determine whether there is poor contact between the first charging interface and the second charging interface, where when it is determined that there is poor contact between the first charging interface and the second charging interface, the control unit controls the power adapter to exit from the first charging mode.

Optionally, as an embodiment, before determining whether the contact between the first charging interface and the second charging interface is poor, the control unit is further configured to receive information indicating a path impedance of the terminal from the terminal, wherein the control unit sends a fourth instruction to the terminal, and the fourth instruction is used for inquiring about a voltage of a battery in the terminal; the control unit receives a reply instruction of the fourth instruction sent by the terminal, wherein the reply instruction of the fourth instruction is used for indicating the voltage of a battery in the terminal; the control unit determines the path impedance of the power adapter to the battery according to the output voltage of the power adapter and the voltage of the battery; the control unit determines whether the first charging interface and the second charging interface are in poor contact or not according to the path impedance from the power adapter to the battery, the path impedance of the terminal and the path impedance of a charging line between the power adapter and the terminal.

The terminal may record its path impedance in advance, for example, the same type of terminal may set the path impedance of the terminal to the same value at the time of factory setting due to the same structure. Likewise, the power adapter may pre-record the path impedance of the charging line. When the power adapter acquires the voltage at the two ends of the battery of the terminal, the path impedance of the whole path can be determined according to the voltage drop from the power adapter to the two ends of the battery and the current of the path, and when the path impedance of the whole path is greater than the path impedance of the terminal + the path impedance of the charging circuit, or the path impedance of the whole path- (the path impedance of the terminal + the path impedance of the charging circuit) > the impedance threshold, it can be considered that the first charging interface is in poor contact with the second charging interface.

Optionally, as an embodiment, before the power adapter exits from the first charging mode, the control unit further sends a fifth instruction to the terminal, where the fifth instruction is used to indicate that the first charging interface and the second charging interface are in poor contact.

After the power adapter sends the fifth command, the first charging mode can be exited or reset.

The quick charging process according to the embodiment of the present invention is described in detail above from the perspective of the power adapter, and the quick charging process according to the embodiment of the present invention will be described below from the perspective of the terminal.

It should be understood that the interaction of the power adapter and the terminal described on the terminal side and the related characteristics, functions, and the like correspond to the description on the power adapter side, and the repeated description is appropriately omitted for the sake of brevity.

According to an embodiment of the present invention, as shown in fig. 13, the terminal 2 further includes a charging control switch 203 and a controller 204, the charging control switch 203 is connected between the second charging interface 201 and the battery 202, for example, a switch circuit formed by an electronic switching device, and the charging control switch 203 is used for turning off or on the charging process of the battery 202 under the control of the controller 204, so that the charging process of the battery 202 can also be controlled from the terminal side, and the charging of the battery 202 is ensured to be safe and reliable.

Also, as shown in fig. 14, terminal 2 further includes communication unit 205, and communication unit 205 is configured to establish bidirectional communication between controller 204 and control unit 107 via second charging interface 201 and first charging interface 105. That is, the terminal 2 and the power adapter 1 can perform bidirectional communication through a data line in the USB interface, the terminal 2 supports a second charging mode and a first charging mode, where a charging current in the first charging mode is greater than a charging current in the second charging mode, and the communication unit 205 performs bidirectional communication with the control unit 107 so that the power adapter 1 determines to use the first charging mode to charge the terminal 2, so that the control unit 107 controls the power adapter 1 to output a charging current corresponding to the first charging mode to charge the battery 202 in the terminal 2.

In the embodiment of the invention, the power adapter 1 does not increase the output current blindly to perform the quick charging, but needs to perform the bidirectional communication with the terminal 2 to negotiate whether the first charging mode can be adopted, so that compared with the prior art, the safety of the quick charging process is improved.

Optionally, as an embodiment, the controller receives, through a communication unit, a first instruction sent by the control unit, where the first instruction is used to inquire whether the terminal turns on the first charging mode; and the controller sends a reply instruction of the first instruction to the control unit through a communication unit, wherein the reply instruction of the first instruction is used for indicating that the terminal agrees to start the first charging mode.

Optionally, as an embodiment, before the controller receives the first instruction sent by the control unit through the communication unit, the power adapter charges the battery in the terminal through the second charging mode, after the control unit determines that the charging duration of the second charging mode is greater than a preset threshold, the control unit sends the first instruction to the communication unit in the terminal, and the controller receives the first instruction sent by the control unit through the communication unit.

Optionally, as an embodiment, before the power adapter outputs the charging current corresponding to the first charging mode to charge the battery in the terminal, the controller performs bidirectional communication with the control unit through a communication unit, so that the power adapter determines the charging voltage corresponding to the first charging mode.

Optionally, as an embodiment, the controller receives a second instruction sent by the control unit, where the second instruction is used to inquire whether a current output voltage of the power adapter is suitable as the charging voltage of the first charging mode; and the controller sends a reply instruction of the second instruction to the control unit, wherein the reply instruction of the second instruction is used for indicating that the current output voltage of the power adapter is proper, higher or lower.

Optionally, as an embodiment, the controller performs bidirectional communication with the control unit so that the power adapter determines the charging current corresponding to the first charging mode.

The controller receives a third instruction sent by the control unit, wherein the third instruction is used for inquiring the maximum charging current currently supported by the terminal; and the controller sends a reply instruction of the third instruction to the control unit, wherein the reply instruction of the third instruction is used for indicating the maximum charging current currently supported by a battery in the terminal, so that the power adapter determines the charging current corresponding to the first charging mode according to the maximum charging current.

Optionally, as an embodiment, in a process that the power adapter charges the terminal using the first charging mode, the controller performs bidirectional communication with the control unit, so that the power adapter continuously adjusts a charging current output by the power adapter to a battery.

The controller receives a fourth instruction sent by the control unit, wherein the fourth instruction is used for inquiring the current voltage of a battery in the terminal; and the controller sends a reply instruction of the fourth instruction to the control unit, wherein the reply instruction of the fourth instruction is used for indicating the current voltage of the battery in the terminal, so that the power adapter continuously adjusts the charging current output to the battery by the power adapter according to the current voltage of the battery.

Optionally, as an embodiment, in a process that the power adapter charges the terminal using the first charging mode, the controller performs bidirectional communication with the control unit through a communication unit, so that the power adapter determines whether there is a poor contact between the first charging interface and the second charging interface.

The controller receives a fourth instruction sent by the control unit, wherein the fourth instruction is used for inquiring the current voltage of a battery in the terminal; and the controller sends a reply instruction of the fourth instruction to the control unit, wherein the reply instruction of the fourth instruction is used for indicating the current voltage of the battery in the terminal, so that the control unit can determine whether the first charging interface is in poor contact with the second charging interface according to the output voltage of the power adapter and the current voltage of the battery.

Optionally, as an embodiment, the controller receives a fifth instruction sent by the control unit, where the fifth instruction is used to indicate that the contact between the first charging interface and the second charging interface is poor.

In order to start and use the first charging mode, the power adapter may perform a fast charging communication procedure with the terminal, and implement fast charging of the battery through one or more handshaking negotiations. The fast charging communication flow and the various stages included in the fast charging process according to the embodiment of the present invention are described in detail below with reference to fig. 6. It should be understood that the communication steps or operations shown in fig. 6 are only examples, and other operations or variations of the various operations in fig. 6 may also be performed by embodiments of the present invention. Moreover, the various stages in FIG. 6 may be performed in a different order than presented in FIG. 6, and not all of the operations in FIG. 6 may be performed. Note that the curve in fig. 6 is a change tendency of the peak value or the average value of the charging current, and is not an actual charging current curve.

As shown in fig. 6, the fast charge process may include five stages:

stage 1:

after the terminal is connected to the power supply device, the terminal may detect the type of the power supply device through the data lines D +, D-, and when it is detected that the power supply device is a power adapter, the current absorbed by the terminal may be greater than a preset current threshold I2 (for example, may be 1A). When the power adapter detects that the output current of the power adapter is greater than or equal to I2 within a preset time period (for example, the time period may be continuous T1), the power adapter considers that the type identification of the terminal for the power supply device is completed, the power adapter starts handshaking communication between the adapter and the terminal, and the power adapter sends an instruction 1 (corresponding to the first instruction) asking whether the terminal starts the first charging mode (or flash charging).

When the power adapter receives the reply instruction of the terminal indicating that the terminal does not agree to turn on the first charging mode, the output current of the power adapter is detected again, and when the output current of the power adapter is still greater than or equal to I2 within a preset continuous time (for example, the time may be a continuous time T1), the request is initiated again to inquire whether the terminal turns on the first charging mode, and the above steps of phase 1 are repeated until the terminal replies that the terminal agrees to turn on the first charging mode, or the output current of the power adapter no longer meets the condition of being greater than or equal to I2.

And after the terminal agrees to start the first charging mode, starting the quick charging process, and entering the stage 2 of the quick charging communication process.

And (2) stage:

the steamed bread wave/trapezoidal wave voltage output by the power adapter can comprise a plurality of gears, and the power adapter sends a command 2 (corresponding to the second command) to the terminal to inquire whether the output voltage of the power adapter of the terminal is matched with the current voltage of the battery (or whether the output voltage is proper or not, namely whether the output voltage is suitable to be used as the charging voltage in the first charging mode), namely whether the charging requirement is met or not.

And the terminal replies that the output voltage of the power adapter is higher or lower or matched, if the power adapter receives feedback that the output voltage of the power adapter is higher or lower, the control unit adjusts the output voltage of the power adapter by one step by adjusting the duty ratio of the PWM signal, sends an instruction 2 to the terminal again and inquires whether the output voltage of the power adapter of the terminal is matched or not again.

And repeating the steps in the stage 2 until the terminal replies that the output voltage of the power adapter is in the matching gear, and entering the stage 3.

And (3) stage:

when the power adapter receives the feedback that the terminal replies matching the output voltage of the power adapter, the power adapter sends an instruction 3 (corresponding to the third instruction) to the terminal, inquires the maximum charging current currently supported by the terminal, and the terminal replies the maximum charging current value currently supported by the power adapter and enters stage 4.

And (4) stage:

after the power adapter receives the feedback of the currently supported maximum charging current value replied by the terminal, the power adapter may set its output current reference value, and the control unit 107 adjusts the duty ratio of the PWM signal according to the current reference value, so that the output current of the power adapter meets the terminal charging current requirement, i.e. enters a constant current phase, where the peak value or average value of the output current of the power adapter is kept substantially unchanged (i.e. the variation amplitude of the peak value or average value of the output current is small, such as within 5% of the peak value or average value of the output current), i.e. the current peak value of the third ripple waveform is kept constant in each period.

And (5) stage:

when the current constant change stage is entered, the power adapter sends an instruction 4 (corresponding to the fourth instruction) at intervals, the current voltage of the terminal battery is inquired, the terminal can feed back the current voltage of the terminal battery to the power adapter, and the power adapter can judge whether the USB contact, namely the contact between the first charging interface and the second charging interface is good and whether the current charging current value of the terminal needs to be reduced according to the feedback of the terminal on the current voltage of the terminal battery. When the power adapter determines that the USB is in poor contact, command 5 (corresponding to the fifth command) is sent, and then reset to re-enter phase 1.

Optionally, in some embodiments, when the terminal replies to instruction 1 in phase 1, data (or information) of the path impedance of the terminal may be attached to the data corresponding to instruction 1, and the terminal path impedance data may be used to determine whether the USB contact is good or not in phase 5.

Alternatively, in some embodiments, in phase 2, from the time the terminal agrees to initiate the first charging mode to the time the power adapter adjusts the voltage to a suitable value may be controlled within a certain range, and the time beyond a predetermined range the terminal may determine that the request is abnormal and perform a quick reset.

Optionally, in some embodiments, in phase 2, the terminal may make feedback to the power adapter regarding the suitability/matching of the output voltage of the power adapter when the output voltage of the power adapter is adjusted to be higher than Δ V (Δ V is about 200-500 mV) compared to the current voltage of the battery. When the terminal feeds back to the power adapter that the output voltage of the power adapter is not appropriate (i.e., higher or lower), the control unit 107 adjusts the duty ratio of the PWM signal according to the voltage sampling value, thereby adjusting the output voltage of the power adapter.

Optionally, in some embodiments, in the phase 4, the adjusting speed of the output current value of the power adapter may be controlled within a certain range, so that the fast charging abnormal interruption caused by the excessively fast adjusting speed may be avoided.

Alternatively, in some embodiments, in phase 5, the variation range of the output current value of the power adapter may be controlled within 5%, that is, it may be regarded as a constant current phase.

Optionally, in some embodiments, in phase 5, the power adapter monitors the charging loop impedance in real time, i.e. the entire charging loop impedance is monitored by measuring the output voltage of the power adapter, the current charging current and the read terminal battery voltage. When the impedance of the charging loop is measured to be more than the impedance of the terminal access and the impedance of the quick charging data line, the USB is considered to have poor contact, and quick charging reset is carried out.

Optionally, in some embodiments, after the first charging mode is turned on, a communication time interval between the power adapter and the terminal may be controlled within a certain range, so as to avoid a quick charge reset.

Optionally, in some embodiments, the stopping of the first charging mode (or fast charging process) may be divided into two categories, a recoverable stopping and an unrecoverable stopping:

for example, when the terminal detects that the battery is fully charged or the USB has poor contact, the fast charge is stopped and reset, and enters stage 1, the terminal does not agree to start the first charging mode, the fast charge communication flow does not enter stage 2, and the fast charge process that is stopped at this time may be an unrecoverable stop.

For another example, when communication between the terminal and the power adapter is abnormal, the fast charging is stopped and reset to enter the phase 1, after the requirement of the phase 1 is met, the terminal agrees to start the first charging mode to recover the fast charging process, and the stopped fast charging process may be a recoverable stop.

For example, when the terminal detects that the battery is abnormal, the quick charging is stopped and reset to enter the phase 1, and after the phase 1 is entered, the terminal does not agree to start the first charging mode. And after the battery recovers to be normal and the requirement of the stage 1 is met, the terminal agrees to start the quick charge to recover the quick charge process, and the quick charge process stopped at the moment can be restorable.

It should be noted that the communication steps or operations shown in fig. 6 above are only examples, for example, in phase 1, after the terminal and the adapter are connected, the handshake communication between the terminal and the adapter may also be initiated by the terminal, that is, the terminal sends instruction 1 to inquire whether the adapter turns on the first charging mode (or referred to as flash charging), and when the terminal receives a reply instruction of the power adapter indicating that the power adapter agrees to turn on the first charging mode, the fast charging process is turned on.

It should be noted that the communication steps or operations shown in fig. 6 are only examples, for example, after phase 5, a constant voltage charging phase may be further included, that is, in phase 5, the terminal may feed back the current voltage of the terminal battery to the power adapter, as the voltage of the terminal battery continuously rises, when the current voltage of the terminal battery reaches a constant voltage charging voltage threshold, the charging shifts to the constant voltage charging phase, and the control unit 107 adjusts the duty ratio of the PWM signal according to the voltage reference value (i.e., the constant voltage charging voltage threshold) so that the output voltage of the power adapter meets the terminal charging voltage requirement, that is, the voltage is kept substantially constant, in the constant voltage charging phase, the charging current gradually decreases, and when the current drops to a certain threshold, the charging is stopped, and the battery is identified to be fully charged. Here, the constant voltage charging here means that the peak voltage of the third ripple waveform is kept substantially constant.

It is understood that, in the embodiment of the present invention, obtaining the output voltage of the power adapter means obtaining a peak voltage or a voltage average value of the third ripple waveform, and obtaining the output current of the power adapter means obtaining a peak current or a current average value of the third ripple waveform.

In one embodiment of the present invention, as shown in fig. 7A, the power adapter 1 further includes: a controllable switch 108 and a filtering unit 109 connected in series, the controllable switch 108 and the filtering unit 109 connected in series being connected to the first output of the second rectifying unit 104, wherein the control unit 107 is further configured to control the controllable switch 108 to be closed when the charging mode is determined to be the second charging mode, and to control the controllable switch 108 to be open when the charging mode is determined to be the first charging mode. In addition, one or more groups of small capacitors are connected in parallel at the output end of the second rectifying unit 104, which not only can reduce noise, but also can reduce surge. Alternatively, an LC filter circuit or a pi filter circuit may be further connected to the output end of the second rectifying unit 104 to filter ripple interference. As shown in fig. 7B, an LC filter circuit is connected to the output terminal of the second rectifying unit 104. It should be noted that, the capacitors in the LC filter circuit or the pi filter circuit are all small capacitors, and the occupied space is small.

The filtering unit 109 includes a filtering capacitor, the filtering capacitor can support a standard charging of 5V, that is, corresponding to the second charging mode, and the controllable switch 108 can be formed by a semiconductor switching device, such as a MOS transistor. When the power adapter charges the battery in the terminal in the second charging mode (or called standard charging), the control unit 107 controls the controllable switch 108 to be closed, and the filtering unit 109 is connected to the circuit, so that the output of the second rectifying unit can be filtered, and the power adapter is better compatible with a direct current charging technology, namely, direct current is loaded to the battery of the terminal, and direct current charging of the battery is realized. For example, the filter unit typically includes an electrolytic capacitor and a common capacitor connected in parallel, i.e., a small capacitor (e.g., a solid capacitor) that supports a 5V standard charge. Because the electrolytic capacitor occupies a larger volume, in order to reduce the size of the power adapter, the electrolytic capacitor in the power adapter can be removed, and a capacitor with a smaller capacitance value is reserved. When the second charging mode is used, the branch where the small capacitor is located can be controlled to be conducted, current is filtered, stable output of small power is achieved, and the battery is charged in a direct current mode; when the first charging mode is used, the branch where the small capacitor is located can be controlled to be disconnected, and the output of the second rectifying unit 104 directly outputs a voltage/current with a pulsating waveform without filtering, and the voltage/current is applied to the battery to realize the quick charging of the battery.

According to an embodiment of the present invention, the control unit 107 is further configured to, when the charging mode is determined to be the first charging mode, obtain a charging current and/or a charging voltage corresponding to the first charging mode according to the state information of the terminal, and adjust a duty ratio of a control signal, such as a PWM signal, according to the charging current and/or the charging voltage corresponding to the first charging mode. That is, when it is determined that the current charging mode is the first charging mode, the control unit 107 obtains the charging current and/or the charging voltage corresponding to the first charging mode according to the obtained state information of the terminal, such as the voltage, the electric quantity, the temperature of the battery, the operation parameters of the terminal, and the power consumption information of the application program running on the terminal, and then adjusts the duty ratio of the control signal according to the obtained charging current and/or charging voltage, so that the output of the power adapter meets the charging requirement, and the rapid charging of the battery is realized.

Wherein the state information of the terminal includes a temperature of the battery. And when the temperature of the battery is greater than a first preset temperature threshold or the temperature of the battery is less than a second preset temperature threshold, if the current charging mode is the first charging mode, the first charging mode is switched to the second charging mode, wherein the first preset temperature threshold is greater than the second preset temperature threshold. That is, when the temperature of the battery is too low (e.g., corresponding to less than the second preset temperature threshold) or too high (e.g., corresponding to greater than the first preset temperature threshold), the battery is not suitable for fast charging, so the first charging mode needs to be switched to the second charging mode. In the embodiment of the present invention, the first preset temperature threshold and the second preset temperature threshold may be set or written in the storage of the control unit (for example, the power adapter MCU) according to actual situations.

In an embodiment of the present invention, the control unit 107 is further configured to control the switch unit 102 to turn off when the temperature of the battery is greater than a preset high-temperature protection threshold, that is, when the temperature of the battery exceeds the high-temperature protection threshold, the control unit 107 needs to adopt a high-temperature protection strategy, and control the switch unit 102 to be in an off state, so that the power adapter stops charging the battery, thereby implementing high-temperature protection on the battery, and improving the charging safety. The high temperature protection threshold may be different from or the same as the first temperature threshold. Preferably, the high temperature protection threshold is greater than the first temperature threshold.

In another embodiment of the present invention, the controller is further configured to obtain a temperature of the battery, and when the temperature of the battery is greater than a preset high temperature protection threshold, control the charging control switch to turn off, that is, turn off the charging control switch through a terminal side, so as to turn off a charging process of the battery, and ensure charging safety.

In addition, in an embodiment of the present invention, the control unit is further configured to acquire a temperature of the first charging interface, and control the switch unit to turn off when the temperature of the first charging interface is greater than a preset protection temperature. That is, when the temperature of the charging interface exceeds a certain temperature, the control unit 107 also needs to execute a high-temperature protection strategy, and controls the switch unit 102 to be switched off, so that the power adapter stops charging the battery, the high-temperature protection of the charging interface is realized, and the charging safety is improved.

Of course, in another embodiment of the present invention, the controller performs bidirectional communication with the control unit to obtain the temperature of the first charging interface, and when the temperature of the first charging interface is greater than a preset protection temperature, the controller controls the charging control switch (see fig. 13 and 14) to turn off, that is, the terminal side turns off the charging control switch, so as to turn off the charging process of the battery, thereby ensuring charging safety.

Specifically, in one embodiment of the present invention, as shown in fig. 8, the power adapter 1 further includes a driving unit 110, such as a MOSFET driver, the driving unit 110 is connected between the switching unit 102 and the control unit 107, and the driving unit 110 is used for driving the switching unit 102 to be turned on or off according to a control signal. Of course, it should be noted that in other embodiments of the present invention, the driving unit 110 may also be integrated in the control unit 107.

As shown in fig. 8, the power adapter 1 further includes an isolation unit 111, and the isolation unit 111 is connected between the driving unit 110 and the control unit 107, and implements signal isolation between the primary and secondary windings of the power adapter 1 (or signal isolation between the primary winding and the secondary winding of the transformer 103). The isolation unit 111 may adopt an optical coupling isolation manner, and may also adopt other isolation manners. By providing the isolation unit 111, the control unit 107 can be provided on the secondary side of the power adapter 1 (or the secondary winding side of the transformer 103), thereby facilitating communication with the terminal 2, making the space design of the power adapter 1 simpler and easier.

Of course, it is understood that in other embodiments of the present invention, the control unit 107 and the driving unit 110 may be disposed on the primary side, and the isolation unit 111 may be disposed between the control unit 107 and the sampling unit 106 to achieve signal isolation between the primary and the secondary of the power adapter 1.

Furthermore, in the embodiment of the present invention, when the control unit 107 is disposed on the secondary side, the isolation unit 111 needs to be disposed, and the isolation unit 111 may also be integrated in the control unit 107. That is, when the primary transfers a signal to the secondary or the secondary transfers a signal to the primary, an isolation unit is generally required to perform signal isolation.

In an embodiment of the present invention, as shown in fig. 9, the power adapter 1 further includes an auxiliary winding and a power supply unit 112, the auxiliary winding generates a voltage with a fourth ripple waveform according to the modulated voltage with the first ripple waveform, the power supply unit 112 is connected to the auxiliary winding, and the power supply unit 112 (for example, includes a filtering and voltage stabilizing module, a voltage converting module, and the like) is configured to convert the voltage with the fourth ripple waveform to output a direct current to respectively supply power to the driving unit 110 and/or the control unit 107. The power supply unit 112 may be formed by a small filtering capacitor, a voltage stabilizing chip, and the like, and implements processing and conversion on the voltage of the fourth ripple waveform to output a low-voltage direct current of 3.3V or 5V, and the like.

That is, the power supply of the driving unit 110 may be obtained by converting the voltage of the fourth ripple waveform by the power supply unit 112, and when the control unit 107 is provided on the primary side, the power supply thereof may also be obtained by converting the voltage of the fourth ripple waveform by the power supply unit 112. As shown in fig. 9, when the control unit 107 is disposed on the primary side, the power supply unit 112 provides two paths of direct current outputs to respectively supply power to the driving unit 110 and the control unit 107, and the optical coupling isolation unit 111 is disposed between the control unit 107 and the sampling unit 106 to implement signal isolation between the primary side and the secondary side of the power adapter 1.

When the control unit 107 is provided on the primary side and the driving unit 110 is integrated, the power supply unit 112 supplies power to the control unit 107 alone. When the control unit 107 is disposed on the secondary side and the driving unit 110 is disposed on the primary side, the power supply unit 112 supplies power to the driving unit 110 alone, and the power supply of the control unit 107 is supplied from the secondary side to the control unit 107 by, for example, converting the voltage of the third ripple waveform output from the second rectifying unit 104 into a direct-current power supply by one power supply unit.

In addition, in the embodiment of the present invention, the output end of the first rectifying unit 101 is also connected in parallel with a plurality of small capacitors, which play a role of filtering. Alternatively, an LC filter circuit is connected to the output terminal of the first rectifying unit 101.

In another embodiment of the present invention, as shown in fig. 10, the power adapter 1 further includes a first voltage detection unit 113, the first voltage detection unit 113 is respectively connected to the auxiliary winding and the control unit 107, the first voltage detection unit 113 is configured to detect a voltage of the fourth ripple waveform to generate a voltage detection value, and the control unit 107 is further configured to adjust a duty ratio of the control signal according to the voltage detection value.

That is, the control unit 107 may reflect the voltage output from the second rectifying unit 104 according to the voltage output from the auxiliary winding detected by the first voltage detecting unit 113, and then adjust the duty ratio of the control signal according to the voltage detection value so that the output from the second rectifying unit 104 matches the charging demand of the battery.

Specifically, in one embodiment of the present invention, as shown in fig. 11, the sampling unit 106 includes: a first current sampling circuit 1061 and a first voltage sampling circuit 1062. The first current sampling circuit 1061 is configured to sample a current output by the second rectifying unit 104 to obtain a current sample value, and the first voltage sampling circuit 1062 is configured to sample a voltage output by the second rectifying unit 104 to obtain a voltage sample value.

Alternatively, the first current sampling circuit 1061 may sample the current output by the second rectifying unit 104 by sampling a voltage across a resistor (current sensing resistor) connected to the first output terminal of the second rectifying unit 104. The first voltage sampling circuit 1062 may sample the voltage output by the second rectifying unit 104 by sampling the voltage between the first output terminal and the second output terminal of the second rectifying unit 104.

Also, in one embodiment of the present invention, as shown in fig. 11, the first voltage sampling circuit 1062 includes a peak voltage sample-and-hold unit, a zero-crossing sampling unit, a bleeding unit, and an AD sampling unit. The peak voltage sampling and holding unit is used for sampling and holding the peak voltage of the third pulsating waveform, the zero-crossing sampling unit is used for sampling the zero-crossing point of the voltage of the third pulsating waveform, the discharging unit is used for discharging the peak voltage sampling and holding unit at the zero-crossing point, and the AD sampling unit is used for sampling the peak voltage in the peak voltage sampling and holding unit to obtain a voltage sampling value.

By arranging the peak voltage sampling and holding unit, the zero-crossing sampling unit, the bleeding unit and the AD sampling unit in the first voltage sampling circuit 1062, accurate sampling of the voltage output by the second rectifying unit 104 can be realized, and it is ensured that the voltage sampling value can be kept synchronous with the voltage of the first ripple waveform, i.e., phase synchronization, and the amplitude variation trend is kept consistent.

According to an embodiment of the present invention, as shown in fig. 12, the power adapter 1 further includes a second voltage sampling circuit 114, the second voltage sampling circuit 114 is configured to sample a voltage of the first ripple waveform, and the second voltage sampling circuit 114 is connected to the control unit 107, where when a voltage value sampled by the second voltage sampling circuit 114 is greater than a first preset voltage value, the control unit 107 controls the switching unit 102 to be turned on for a first preset time to perform a discharging operation on a surge voltage, a spike voltage, and the like in the first ripple waveform.

As shown in fig. 12, the second voltage sampling circuit 114 may be connected to the first output end and the second output end of the first rectifying unit 101, so as to sample a voltage of the first ripple waveform, the control unit 107 determines a voltage value sampled by the second voltage sampling circuit 114, if the voltage value sampled by the second voltage sampling circuit 114 is greater than a first preset voltage value, it is indicated that the power adapter 1 is interfered by a lightning stroke, and a surge voltage occurs, and at this time, the surge voltage needs to be discharged, so as to ensure the safety and reliability of charging, the control unit 107 controls the switching unit 102 to be turned on for a period of time, so as to form a discharge path, and the surge voltage caused by the lightning stroke is discharged, so as to prevent the power adapter from interfering with the terminal when the terminal is charged by the lightning stroke, and effectively improve the safety and reliability of the terminal when the terminal is charged. The first preset voltage value can be calibrated according to actual conditions.

In an embodiment of the present invention, in a process that the power adapter 1 charges the battery 202 of the terminal 2, the control unit 107 is further configured to control the switch unit 102 to turn off when the voltage value sampled by the sampling unit 106 is greater than a second preset voltage value, that is, the control unit 107 further determines a magnitude of the voltage value sampled by the sampling unit 106, if the voltage value sampled by the sampling unit 106 is greater than the second preset voltage value, it indicates that the voltage output by the power adapter 1 is too high, at this time, the control unit 107 controls the switch unit 102 to turn off, so that the power adapter 1 stops charging the battery 202 of the terminal 2, that is, the control unit 107 controls the switch unit 102 to turn off, so as to implement overvoltage protection of the power adapter 1, and ensure charging safety.

Of course, in an embodiment of the present invention, the controller 204 performs bidirectional communication with the control unit 107 to obtain the voltage value sampled by the sampling unit 106 (fig. 13 and 14), and when the voltage value sampled by the sampling unit 106 is greater than a second preset voltage value, controls the charging control switch 203 to turn off, that is, the charging control switch 203 is turned off by the terminal 2 side, so as to turn off the charging process of the battery 202, thereby ensuring charging safety.

Moreover, the control unit 107 is further configured to control the switch unit 102 to turn off when the current value sampled by the sampling unit 106 is greater than the preset current value, that is, the control unit 107 further determines the magnitude of the current value sampled by the sampling unit 106, if the current value sampled by the sampling unit 106 is greater than the preset current value, it indicates that the current output by the power adapter 1 is too large, and at this time, the control unit 107 controls the switch unit 102 to turn off, so that the power adapter 1 stops charging the terminal, that is, the control unit 107 controls the switch unit 102 to turn off to implement overcurrent protection of the power adapter 1, thereby ensuring charging safety.

Similarly, the controller 204 performs bidirectional communication with the control unit 107 to obtain the current value sampled by the sampling unit 106 (fig. 13 and 14), and when the current value sampled by the sampling unit 106 is greater than the preset current value, controls the charging control switch 203 to turn off, that is, the charging control switch 203 is turned off through the terminal 2 side, so as to turn off the charging process of the battery 202, thereby ensuring charging safety.

The second preset voltage value and the preset current value can be set or written into the memory of the control unit (for example, in the control unit 107 of the power adapter 1, for example, in the micro control processor MCU) according to actual conditions.

In an embodiment of the present invention, the terminal may be a mobile terminal such as a mobile phone, a mobile power source such as a mobile phone, a multimedia player, a notebook computer, a wearable device, and the like.

According to the charging system provided by the embodiment of the invention, the power adapter is controlled to output the voltage with the third ripple waveform, and the voltage with the third ripple waveform output by the power adapter is directly loaded to the battery of the terminal, so that the battery can be directly and quickly charged by the ripple output voltage/current. Compared with the traditional constant voltage and constant current, the pulse output voltage/current is periodically changed, the lithium separation phenomenon of the lithium battery can be reduced, the service life of the battery is prolonged, the probability and the strength of arc discharge of a contact of a charging interface can be reduced, the service life of the charging interface is prolonged, the polarization effect of the battery is favorably reduced, the charging speed is increased, the heat generation of the battery is reduced, and the safety and the reliability of the terminal during charging are ensured. In addition, because the power adapter outputs the voltage with the pulsating waveform, an electrolytic capacitor is not required to be arranged in the power adapter, so that the simplification and the miniaturization of the power adapter can be realized, and the cost can be greatly reduced. Moreover, the compatibility of the current detection function in the detection precision and the dynamic range can be ensured by switching the two current sampling modes of the first current sampling circuit, and the application range is expanded.

Furthermore, an embodiment of the present invention further provides a charging system, including: a terminal; the power adapter is used for charging the terminal.

An embodiment of the present invention further provides a power adapter, including: a first rectifying unit for rectifying an input alternating current to output a voltage of a first ripple waveform; a switching unit for modulating a voltage of the first ripple waveform according to a control signal; a transformer for outputting a voltage of a second ripple waveform according to the modulated voltage of the first ripple waveform; a second rectifying unit for rectifying the voltage of the second ripple waveform to output a voltage of a third ripple waveform; the first charging interface is used for loading the voltage of the third ripple waveform to a battery of the terminal through the second charging interface when the first charging interface is connected with the second charging interface of the terminal, wherein the second charging interface is connected with the battery; the first current sampling circuit is used for sampling the current output by the second rectifying unit to obtain a current sampling value, and comprises a first current sampling mode and a second current sampling mode; a changeover switch unit for controlling the first current sampling circuit to switch between the first current sampling mode and the second current sampling mode; the control unit outputs the control signal to the switch unit, controls the switch unit to control the first current sampling circuit to switch the current sampling mode according to the charging mode, and adjusts the duty ratio of the control signal according to the current sampling value so that the voltage of the third pulse waveform meets the charging requirement.

According to the power adapter provided by the embodiment of the invention, the voltage of the third pulse waveform is output through the first charging interface, and the voltage of the third pulse waveform is directly loaded to the battery of the terminal through the second charging interface of the terminal, so that the battery can be directly and quickly charged by the pulse output voltage/current. Compared with the traditional constant voltage and constant current, the pulse output voltage/current is periodically changed, the lithium separation phenomenon of the lithium battery can be reduced, the service life of the battery is prolonged, the probability and the strength of arc discharge of a contact of a charging interface can be reduced, the service life of the charging interface is prolonged, the polarization effect of the battery is favorably reduced, the charging speed is increased, the heat generation of the battery is reduced, and the safety and the reliability of the terminal during charging are ensured. In addition, because the voltage with the pulsating waveform is output, an electrolytic capacitor is not needed, the simplification and the miniaturization of the power adapter can be realized, and the cost can be greatly reduced. Moreover, the compatibility of the current detection function in the detection precision and the dynamic range can be ensured by switching the two current sampling modes of the first current sampling circuit, and the application range is expanded.

Fig. 15 is a flowchart of a charging method for a terminal according to an embodiment of the present invention. As shown in fig. 15, the charging method for a terminal includes the steps of:

and S1, when the first charging interface of the power adapter is connected with the second charging interface of the terminal, rectifying the alternating current input into the power adapter once to output the voltage with the first ripple waveform.

That is, an ac mains of an input ac (i.e., a mains, for example, 220V, 50Hz, or 60Hz) is rectified by a first rectifying unit in the power adapter, and a steamed bun wave voltage of a first pulsating waveform (for example, 100Hz or 120Hz) is output.

And S2, modulating the voltage of the first ripple waveform by controlling the switch unit, and outputting the voltage of the second ripple waveform by transformation of the transformer.

The switch unit can be composed of MOS tubes, and the PWM control is carried out on the MOS tubes to carry out chopping modulation on the steamed bread wave voltage. Then, the modulated voltage of the first ripple waveform is coupled to the secondary side by a transformer, and the voltage of the second ripple waveform is output by the secondary winding.

In the embodiment of the invention, a high-frequency transformer can be adopted for conversion, so that the volume of the transformer can be small, and the high-power and miniaturized design of the power adapter can be realized.

And S3, performing secondary rectification on the voltage with the second ripple waveform to output a voltage with a third ripple waveform, wherein the voltage with the third ripple waveform can be loaded to the battery at the terminal through the second charging interface, so as to charge the battery at the terminal.

In an embodiment of the present invention, the second rectifying unit performs secondary rectification on the voltage of the second ripple waveform, and the second rectifying unit may be formed by a diode or a MOS transistor, so as to implement secondary synchronous rectification, so that the modulated first ripple waveform and the modulated third ripple waveform are kept synchronous.

And S4, sampling the twice rectified current through a first current sampling circuit to obtain a current sampling value, wherein the first current sampling circuit comprises a first current sampling mode and a second current sampling mode.

And S5, controlling the first current sampling circuit to switch the current sampling mode according to the charging mode, and adjusting the duty ratio of the control signal according to the current sampling value so that the voltage of the third pulse waveform meets the charging requirement.

According to an embodiment of the invention, the frequency of the control signal is further adjusted according to the current sample value.

In addition, the voltage after secondary rectification can be sampled to obtain a voltage sampling value, and the duty ratio of a control signal for controlling the switch unit is adjusted according to the voltage sampling value and/or the current sampling value, so that the voltage of the third pulse waveform meets the charging requirement

The voltage of the third ripple waveform satisfies the charging requirement, which means that the voltage and the current of the third ripple waveform need to satisfy the charging voltage and the charging current when the battery is charged. That is to say, the duty ratio of a control signal, for example, a PWM signal, may be adjusted according to the sampled voltage and/or current output by the power adapter, the output of the power adapter may be adjusted in real time, and closed-loop adjustment control may be implemented, so that the voltage of the third ripple waveform meets the charging requirement of the terminal, and the battery is ensured to be charged safely and reliably, specifically, the charging voltage waveform output to the battery is adjusted by the duty ratio of the PWM signal as shown in fig. 3, and the charging current waveform output to the battery is adjusted by the duty ratio of the PWM signal as shown in fig. 4A.

Therefore, in the embodiment of the invention, the switch unit is controlled to directly perform PWM chopping modulation on the voltage of the first pulsating waveform after full-bridge rectification, namely the steamed bread wave voltage, the voltage is sent to the high-frequency transformer, the voltage is coupled from the primary side to the secondary side through the high-frequency transformer, and then the voltage/current is reduced into the steamed bread wave voltage/current after synchronous rectification and can also be modulated into the trapezoidal wave voltage/current to be directly sent to the battery of the terminal, so that the rapid charging of the battery is realized. The voltage amplitude of the steamed bun waves/trapezoidal waves can be adjusted through the duty ratio of the PWM signals, and the output of the power adapter meets the charging requirement of the battery. Therefore, primary and secondary electrolytic capacitors in the power adapter can be eliminated, and the battery is directly charged through the steamed bread wave/trapezoidal wave voltage, so that the size of the power adapter can be reduced, the miniaturization of the power adapter is realized, and the cost can be greatly reduced.

In one embodiment of the invention, when the terminal is bidirectionally communicated with the data line in the first charging interface to determine to use the first charging mode to charge the terminal, the first current sampling circuit is controlled to be in the first current sampling mode; and when the bidirectional communication is carried out with the terminal through the data line in the first charging interface so as to determine that the terminal is charged by using the second charging mode, controlling the first current sampling circuit to be in the second current sampling mode.

According to an embodiment of the invention, the frequency of the control signal is adjusted according to the voltage sampling value and/or the current sampling value, so that the PWM signal output to the switching unit can be controlled to be output for a period of time and then to be stopped, and the output of the PWM signal is started again after the predetermined time is stopped, so that the voltage loaded to the battery is intermittent, and the intermittent charging of the battery is realized, thereby avoiding the potential safety hazard caused by serious heating when the battery is continuously charged, and improving the charging reliability and safety of the battery. The control signal output to the switching unit may be as shown in fig. 5.

Further, the above charging method for a terminal further includes: the terminal is communicated with the first charging interface to acquire the state information of the terminal, and the duty ratio of the control signal is adjusted according to the state information of the terminal, the voltage sampling value and/or the current sampling value.

That is to say, when the second charging interface is connected to the first charging interface, the power adapter and the terminal may send a communication inquiry command to each other, and after receiving a corresponding response command, the power adapter and the terminal may establish a communication connection, so that the state information of the terminal may be obtained, and thus, the charging mode and the charging parameters (such as charging current and charging voltage) may be negotiated with the terminal, and the charging process may be controlled.

According to an embodiment of the invention, the voltage of the fourth ripple waveform is generated through transformation of the transformer, and the voltage of the fourth ripple waveform is detected to generate a voltage detection value, so that the duty ratio of the control signal is adjusted according to the voltage detection value.

Specifically, the transformer may further include an auxiliary winding, and the auxiliary winding may generate a voltage of a fourth ripple waveform according to the modulated voltage of the first ripple waveform, so that the output voltage of the power adapter may be reflected by detecting the voltage of the fourth ripple waveform, and the duty ratio of the control signal may be adjusted according to the voltage detection value, so that the output of the power adapter matches the charging requirement of the battery.

In one embodiment of the present invention, sampling the twice rectified voltage to obtain a voltage sample value includes: sampling and holding the peak voltage of the secondarily rectified voltage, and sampling the zero crossing point of the secondarily rectified voltage; the peak voltage sampling and holding unit is used for carrying out discharging on the peak voltage sampled and held at the zero crossing point; sampling a peak voltage in the peak voltage sample-and-hold unit to obtain the voltage sample value. Therefore, accurate sampling of the voltage output by the power adapter can be achieved, and the voltage sampling value can be kept synchronous with the voltage of the first ripple waveform, namely the phase and amplitude variation trends are kept consistent.

Further, in an embodiment of the present invention, the above charging method for a terminal further includes: and sampling the voltage of the first ripple waveform, and controlling the switch unit to be switched on for a first preset time to discharge surge voltage in the first ripple waveform when the sampled voltage value is greater than a first preset voltage value.

The voltage of the first pulse waveform is sampled, then the sampled voltage value is judged, if the sampled voltage value is larger than a first preset voltage value, the fact that the power adapter is interfered by lightning stroke is explained, surge voltage occurs, the surge voltage needs to be discharged at the moment, the charging safety and reliability are guaranteed, the control switch unit needs to be controlled to be opened for a period of time, a discharging passage is formed, the surge voltage caused by the lightning stroke is discharged, the interference caused when the lightning stroke charges the terminal to the power adapter is prevented, and the safety and reliability of the terminal during charging are effectively improved. The first preset voltage value can be calibrated according to actual conditions.

According to an embodiment of the invention, the terminal is further communicated with the first charging interface to determine a charging mode, and when the charging mode is determined to be the first charging mode, the charging current and/or the charging voltage corresponding to the first charging mode are acquired according to the state information of the terminal, so as to adjust the duty ratio of the control signal according to the charging current and/or the charging voltage corresponding to the first charging mode, wherein the charging mode includes the first charging mode and the second charging mode.

That is, when it is determined that the current charging mode is the first charging mode, the charging current and/or the charging voltage corresponding to the first charging mode may be obtained according to the obtained state information of the terminal, for example, the voltage, the electric quantity, the temperature of the battery, the operation parameter of the terminal, and the power consumption information of the application program running on the terminal, and then the duty ratio of the control signal is adjusted according to the obtained charging current and/or charging voltage, so that the output of the power adapter meets the charging requirement, and the rapid charging of the battery is realized.

Wherein the state information of the terminal includes a temperature of the battery. And when the temperature of the battery is greater than a first preset temperature threshold or the temperature of the battery is less than a second preset temperature threshold, if the current charging mode is a first charging mode, switching the first charging mode to a second charging mode, wherein the first preset temperature threshold is greater than the second preset temperature threshold. That is, when the temperature of the battery is too low (e.g., corresponding to less than the second preset temperature threshold) or too high (e.g., corresponding to greater than the first preset temperature threshold), the battery is not suitable for fast charging, so the first charging mode needs to be switched to the second charging mode. In the embodiment of the invention, the first preset temperature threshold and the second preset temperature threshold can be calibrated according to actual conditions.

In an embodiment of the present invention, when the temperature of the battery is greater than a preset high-temperature protection threshold, the switch unit is controlled to be turned off, that is, when the temperature of the battery exceeds the high-temperature protection threshold, a high-temperature protection strategy needs to be adopted, and the switch unit is controlled to be turned off, so that the power adapter stops charging the battery, thereby implementing high-temperature protection on the battery and improving the charging safety. The high temperature protection threshold may be different from or the same as the first temperature threshold. Preferably, the high temperature protection threshold is greater than the first temperature threshold.

In another embodiment of the present invention, the terminal further obtains the temperature of the battery, and controls the battery to stop charging when the temperature of the battery is greater than a preset high temperature protection threshold, that is, the terminal side may turn off the charging control switch, so as to turn off the charging process of the battery, and ensure charging safety.

Also, in an embodiment of the present invention, the charging method for a terminal further includes: and acquiring the temperature of the first charging interface, and controlling the switch unit to be switched off when the temperature of the first charging interface is greater than a preset protection temperature. When the temperature of the charging interface exceeds a certain temperature, the control unit also needs to execute a high-temperature protection strategy, and the control switch unit is switched off, so that the power adapter stops charging the battery, the high-temperature protection of the charging interface is realized, and the charging safety is improved.

Of course, in another embodiment of the present invention, the terminal performs bidirectional communication with the power adapter through the second charging interface to obtain the temperature of the first charging interface, and controls the battery to stop charging when the temperature of the first charging interface is greater than a preset protection temperature. Namely, the charging control switch can be turned off through the terminal side, so that the charging process of the battery is turned off, and the charging safety is ensured.

And in the process that the power adapter charges the terminal, when the voltage sampling value is greater than a second preset voltage value, the switch unit is controlled to be switched off. That is to say, in the process that the power adapter charges the terminal, the magnitude of the voltage sampling value is also judged, if the voltage sampling value is greater than the second preset voltage value, it indicates that the voltage output by the power adapter is too high, and at this time, the power adapter is turned off by controlling the switch unit, so that the power adapter stops charging the terminal, that is, overvoltage protection of the power adapter is realized by controlling the switch unit to turn off, and charging safety is ensured.

Of course, in an embodiment of the present invention, the terminal performs bidirectional communication with the power adapter through the second charging interface to obtain the voltage sampling value, and controls the battery to stop charging when the voltage sampling value is greater than a second preset voltage value, that is, the terminal side may turn off the charging control switch, so as to turn off the charging process of the battery, and ensure charging safety.

In an embodiment of the invention, in the process that the power adapter charges the terminal, when the current sampling value is greater than a preset current value, the switching unit is controlled to be turned off. That is to say, in the process that the power adapter charges the terminal, the magnitude of the current sampling value is also judged, if the current sampling value is greater than the preset current value, it indicates that the current output by the power adapter is too large, and at this time, the power adapter stops charging the terminal by controlling the switching-off of the switching unit, that is, the overcurrent protection of the power adapter is realized by controlling the switching-off of the switching unit, so that the charging safety is ensured.

Similarly, the terminal performs bidirectional communication with the power adapter through the second charging interface to obtain the current sampling value, and controls the battery to stop charging when the current sampling value is greater than a preset current value, that is, the terminal side can turn off the charging control switch, so that the charging process of the battery is turned off, and the charging safety is ensured.

And the second preset voltage value and the preset current value can be calibrated according to actual conditions.

In an embodiment of the present invention, the state information of the terminal may include a power amount of the battery, a temperature of the battery, a voltage/current of the terminal, interface information of the terminal, information of a path impedance of the terminal, and the like.

Specifically, the power adapter and the terminal may be connected through a USB interface, which may be a common USB interface or a micro USB interface. The data line in the USB interface, that is, the data line in the first charging interface, is used for bidirectional communication between the power adapter and the terminal, where the data line may be a D + line and/or a D-line in the USB interface, and the bidirectional communication may refer to information interaction between the power adapter and the terminal.

Optionally, as an embodiment, when the power adapter performs bidirectional communication with the terminal through the first charging interface to determine that the terminal is charged using the first charging mode, the power adapter sends a first instruction to the terminal, where the first instruction is used to inquire whether the terminal turns on the first charging mode; and the power adapter receives a reply instruction of the first instruction from the terminal, wherein the reply instruction of the first instruction is used for indicating that the terminal agrees to start the first charging mode.

Optionally, as an embodiment, before the power adapter sends the first instruction to the terminal, the power adapter and the terminal are charged through the second charging mode, and after it is determined that a charging duration of the second charging mode is greater than a preset threshold, the power adapter sends the first instruction to the terminal.

It can be understood that, after the power adapter determines that the charging duration of the second charging mode is greater than the preset threshold, the power adapter may regard that the terminal has identified itself as the power adapter, and may start the fast charging inquiry communication.

Optionally, as an embodiment, the switch unit is further controlled to control the power adapter to adjust the charging current to the charging current corresponding to the first charging mode, and before the power adapter charges the terminal with the charging current corresponding to the first charging mode, the power adapter performs bidirectional communication with the terminal through the first charging interface to determine the charging voltage corresponding to the first charging mode, and controls the power adapter to adjust the charging voltage to the charging voltage corresponding to the first charging mode.

Optionally, as an embodiment, the performing bidirectional communication with the terminal through the first charging interface to determine the charging voltage corresponding to the first charging mode includes: the power adapter sends a second instruction to the terminal, wherein the second instruction is used for inquiring whether the current output voltage of the power adapter is suitable for being used as the charging voltage of the first charging mode; the power adapter receives a reply instruction of the second instruction sent by the terminal, wherein the reply instruction of the second instruction is used for indicating that the current output voltage of the power adapter is proper, higher or lower; and the power adapter determines the charging voltage of the first charging mode according to the reply instruction of the second instruction.

Optionally, as an embodiment, before controlling the power adapter to adjust the charging current to the charging current corresponding to the first charging mode, bidirectional communication is further performed with the terminal through the first charging interface to determine the charging current corresponding to the first charging mode.

Optionally, as an embodiment, the performing bidirectional communication with the terminal through the first charging interface to determine the charging current corresponding to the first charging mode includes: the power adapter sends a third instruction to the terminal, wherein the third instruction is used for inquiring the maximum charging current currently supported by the terminal; the power adapter receives a reply instruction of the third instruction sent by the terminal, wherein the reply instruction of the third instruction is used for indicating the maximum charging current currently supported by the terminal; and the power adapter determines the charging current of the first charging mode according to a reply instruction of the third instruction.

Optionally, as an embodiment, in a process that the power adapter charges the terminal using the first charging mode, bidirectional communication is further performed with the terminal through the first charging interface, so as to continuously adjust a charging current output by the power adapter to the battery by controlling the switch unit.

The power adapter can continuously inquire the current state information of the terminal, so that the charging current is continuously adjusted, such as the battery voltage, the battery capacity and the like of the terminal.

Optionally, as an embodiment, the performing bidirectional communication with the terminal through the first charging interface to continuously adjust the charging current output by the power adapter to the battery by controlling the switch unit includes: the power adapter sends a fourth instruction to the terminal, wherein the fourth instruction is used for inquiring the current voltage of a battery in the terminal; the power adapter receives a reply instruction of the fourth instruction sent by the terminal, wherein the reply instruction of the fourth instruction is used for indicating the current voltage of a battery in the terminal; and adjusting the charging current by controlling the switching unit according to the current voltage of the battery.

Optionally, as an embodiment, the adjusting the charging current by controlling the switching unit according to the current voltage of the battery includes: and adjusting the charging current output to the battery by the power adapter to the charging current value corresponding to the current voltage of the battery by controlling the switch unit according to the current voltage of the battery and the corresponding relation between the preset battery voltage value and the charging current value.

Specifically, the power adapter may store in advance a correspondence relationship between the battery voltage value and the charging current value.

Optionally, as an embodiment, in a process that the power adapter charges the terminal using the first charging mode, the power adapter further performs bidirectional communication with the terminal through the first charging interface to determine whether the first charging interface and the second charging interface are in poor contact, where when it is determined that the first charging interface and the second charging interface are in poor contact, the power adapter is controlled to exit from the first charging mode.

Optionally, as an embodiment, before determining whether the contact between the first charging interface and the second charging interface is poor, the power adapter receives information indicating a path impedance of the terminal from the terminal, wherein the power adapter sends a fourth instruction to the terminal, and the fourth instruction is used for inquiring about a voltage of a battery in the terminal; the power adapter receives a reply instruction of the fourth instruction sent by the terminal, wherein the reply instruction of the fourth instruction is used for indicating the voltage of a battery in the terminal; determining a path impedance of the power adapter to the battery according to the output voltage of the power adapter and the voltage of the battery; and determining whether the first charging interface and the second charging interface are in poor contact or not according to the path impedance from the power adapter to the battery, the path impedance of the terminal and the path impedance of a charging line between the power adapter and the terminal.

Optionally, as an embodiment, before controlling the power adapter to exit the first charging mode, a fifth instruction is further sent to the terminal, where the fifth instruction is used to indicate that the contact between the first charging interface and the second charging interface is poor.

In an embodiment of the present invention, the terminal supports a second charging mode and a first charging mode, where a charging current of the first charging mode is greater than a charging current of the second charging mode, and the terminal performs bidirectional communication with the power adapter through the second charging interface so that the power adapter determines to use the first charging mode to charge the terminal, where the power adapter outputs according to the charging current corresponding to the first charging mode to charge a battery in the terminal.

Optionally, as an embodiment, the performing, by the terminal, bidirectional communication with the power adapter through the second charging interface so that the power adapter determines to use the first charging mode to charge the terminal includes: the terminal receives a first instruction sent by the power adapter, wherein the first instruction is used for inquiring whether the terminal starts the first charging mode; and the terminal sends a reply instruction of the first instruction to the power adapter, wherein the reply instruction of the first instruction is used for indicating that the terminal agrees to start the first charging mode.

Optionally, as an embodiment, before the terminal receives the first instruction sent by the power adapter, the terminal and the power adapter are charged through the second charging mode, and after the power adapter determines that a charging duration of the second charging mode is greater than a preset threshold, the terminal receives the first instruction sent by the power adapter.

Optionally, as an embodiment, the power adapter outputs a charging current corresponding to the first charging mode, so that before the terminal charges a battery in the terminal, the terminal performs bidirectional communication with the power adapter through the second charging interface, so that the power adapter determines a charging voltage corresponding to the first charging mode.

Optionally, as an embodiment, the performing, by the terminal, bidirectional communication with the power adapter through the second charging interface so that the power adapter determines the charging voltage corresponding to the first charging mode includes: the terminal receives a second instruction sent by the power adapter, wherein the second instruction is used for inquiring whether the current output voltage of the power adapter is suitable for being used as the charging voltage of the first charging mode; and the terminal sends a reply instruction of the second instruction to the power adapter, wherein the reply instruction of the second instruction is used for indicating that the current output voltage of the power adapter is proper, higher or lower.

Optionally, as an embodiment, before the terminal receives the charging current corresponding to the first charging mode from the power adapter and charges the battery in the terminal, the terminal performs bidirectional communication with the power adapter through the second charging interface, so that the power adapter determines the charging current corresponding to the first charging mode.

The bidirectional communication between the terminal and the power adapter through the second charging interface is performed so that the power adapter determines the charging current corresponding to the first charging mode, and the method includes: the terminal receives a third instruction sent by the power adapter, wherein the third instruction is used for inquiring the maximum charging current currently supported by the terminal; and the terminal sends a reply instruction of the third instruction to the power adapter, wherein the reply instruction of the third instruction is used for indicating the maximum charging current currently supported by the terminal, so that the power adapter determines the charging current corresponding to the first charging mode according to the maximum charging current.

Optionally, as an embodiment, in a process that the power adapter charges the terminal using the first charging mode, the terminal performs bidirectional communication with the power adapter through the second charging interface, so that the power adapter continuously adjusts a charging current output by the power adapter to a battery.

Wherein, the terminal carries out two-way communication with the power adapter through the second interface that charges, so that the power adapter constantly adjusts the charging current that the power adapter exported to the battery, include: the terminal receives a fourth instruction sent by the power adapter, wherein the fourth instruction is used for inquiring the current voltage of a battery in the terminal; and the terminal sends a reply instruction of the fourth instruction to the power adapter, wherein the reply instruction of the fourth instruction is used for indicating the current voltage of the battery in the terminal so as to continuously adjust the charging current output to the battery by the power adapter according to the current voltage of the battery.

Optionally, as an embodiment, in a process that the power adapter charges the terminal using the first charging mode, the terminal performs bidirectional communication with the power adapter through the second charging interface, so that the power adapter determines whether there is a poor contact between the first charging interface and the second charging interface.

The terminal carries out bidirectional communication with the power adapter through the second charging interface so that the power adapter can determine whether the first charging interface is in poor contact with the second charging interface, and the method comprises the following steps: the terminal receives a fourth instruction sent by the power adapter, wherein the fourth instruction is used for inquiring the current voltage of a battery in the terminal; and the terminal sends a reply instruction of the fourth instruction to the power adapter, wherein the reply instruction of the fourth instruction is used for indicating the current voltage of the battery in the terminal, so that the power adapter can determine whether the first charging interface is in poor contact with the second charging interface according to the output voltage of the power adapter and the current voltage of the battery.

Optionally, as an embodiment, the terminal further receives a fifth instruction sent by the power adapter, where the fifth instruction is used to indicate that the contact between the first charging interface and the second charging interface is poor.

In order to start and use the first charging mode, the power adapter may perform a fast charging communication procedure with the terminal, and implement fast charging of the battery through one or more handshaking negotiations. Referring to fig. 6, the fast charging communication flow and the various stages included in the fast charging process according to the embodiment of the present invention are described in detail. It should be understood that the communication steps or operations shown in fig. 6 are only examples, and other operations or variations of the various operations in fig. 6 may also be performed by embodiments of the present invention. Moreover, the various stages in FIG. 6 may be performed in a different order than presented in FIG. 6, and not all of the operations in FIG. 6 may be performed.

In summary, according to the charging method for the terminal in the embodiment of the present invention, the power adapter is controlled to output the voltage with the third ripple waveform meeting the charging requirement, and the voltage with the third ripple waveform output by the power adapter is directly applied to the battery of the terminal, so that the battery can be directly and rapidly charged by the ripple output voltage/current. Compared with the traditional constant voltage and constant current, the pulse output voltage/current is periodically changed, the lithium separation phenomenon of the lithium battery can be reduced, the service life of the battery is prolonged, the probability and the strength of arc discharge of a contact of a charging interface can be reduced, the service life of the charging interface is prolonged, the polarization effect of the battery is favorably reduced, the charging speed is increased, the heat generation of the battery is reduced, and the safety and the reliability of the terminal during charging are ensured. In addition, because the power adapter outputs the voltage with the pulsating waveform, an electrolytic capacitor is not required to be arranged in the power adapter, so that the simplification and the miniaturization of the power adapter can be realized, and the cost can be greatly reduced. Moreover, the compatibility of the current detection function in the detection precision and the dynamic range can be ensured by switching the two current sampling modes of the first current sampling circuit, and the application range is expanded.

According to an embodiment of the present invention, there is also provided a charging method for a terminal, in which the terminal is charged through a power adapter, and a first capacitor bank and a second capacitor bank are connected to a secondary side of the power adapter. As shown in fig. 16, the charging method includes the steps of:

s1601, primary rectification is performed on the input ac power to output a voltage of a first ripple waveform.

And S1602, modulating the voltage of the first ripple waveform by controlling a switch unit in the power adapter, and outputting the voltage of the second ripple waveform by transformation of the transformer.

S1603, the voltage of the second ripple waveform is rectified twice to output a voltage of a third ripple waveform.

And S1604, performing current sampling on the output after secondary rectification to obtain a current sampling value, and judging the output current of the power adapter according to the current sampling value when the power adapter enters the first charging mode.

And S1605, shielding the first capacitor bank when the output current of the power adapter is at the rising edge or the falling edge.

And S1606, when the output current of the power adapter is in the platform section, enabling the first capacitor bank to work.

When power adapter's output current was in the platform section, with first electric capacity group access circuit, at this moment first electric capacity group perception can not arrive outside AC frequency ripple, and it is all high frequency switch ripple, just so can guarantee that the temperature rise of first electric capacity group can not be too high, can also promote the filtering effect simultaneously.

According to one embodiment of the invention, the first capacitor bank comprises a plurality of solid state capacitors connected in parallel and the second capacitor bank comprises a plurality of ceramic capacitors connected in parallel.

The power adapter further comprises a selection switch, one end of the selection switch is connected with the first capacitor bank, the other end of the selection switch is grounded, and a control end of the selection switch is connected with the control unit, wherein when the output current of the power adapter is at a rising edge or a falling edge, the selection switch is controlled to be switched off; and when the output current of the power adapter is in the platform section, controlling the selection switch to be closed.

That is, when the power adapter enters the first charging mode, i.e., the fast charging mode, the selection switch, e.g., MOSFET, is controlled. When the output current of the power adapter is at a rising edge or a falling edge, the MOSFET is closed, the cathode of the solid capacitor of the first capacitor bank is disconnected with the ground GND, the solid capacitor is shielded, and the ceramic capacitor of the second capacitor bank plays a role in filtering; when the output current of the power adapter is in the platform section, the MOSFET is turned on, so that the solid capacitor of the first capacitor bank is connected into the circuit, and the filtering operation is also carried out.

According to an embodiment of the invention, when the power adapter enters a second charging mode, the first capacitor bank is enabled to operate, wherein the charging speed of the first charging mode is greater than that of the second charging mode.

That is to say, when the power adapter enters the second charging mode, i.e. the normal charging mode, the selection switch, e.g. the MOSFET, is controlled, i.e. the MOSFET is turned on, the cathode of the solid-state capacitor of the first capacitor bank is connected to the ground GND, so that the solid-state capacitor can operate, at this time, the solid-state capacitor of the first capacitor bank and the ceramic capacitor of the second capacitor bank operate simultaneously, and can provide a low-power 5V output, the solid-state capacitor mainly provides the output power when the input voltage of the power adapter is at the valley, because the load output by the power adapter is small, the temperature rise of the solid-state capacitor is controllable, and the ceramic capacitor plays a role in filtering and removing noise.

In an embodiment of the present invention, the power adapter further includes a first charging interface, where the first charging interface includes a power line and a data line, the power line is used to charge a battery of a terminal, and the data line is used to communicate with the terminal, where when the first charging interface is connected with a second charging interface of the terminal, the first charging interface communicates with the terminal to determine a charging mode, and the charging mode includes a first charging mode and a second charging mode.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A power adapter, comprising:

a first rectifying unit for rectifying an input alternating current to output a voltage of a first ripple waveform;

a switching unit for modulating a voltage of the first ripple waveform according to a control signal;

a transformer for outputting a voltage of a second ripple waveform according to the modulated voltage of the first ripple waveform;

a second rectifying unit for rectifying the voltage of the second ripple waveform to output a voltage of a third ripple waveform;

a first current sampling circuit for current sampling an output of the second rectifying unit to obtain a current sample value;

the first capacitor bank and the second capacitor bank are respectively connected to the output end of the second rectifying unit;

the control unit is respectively connected with the first current sampling circuit and the switch unit, and is used for outputting the control signal to the switch unit and judging the output current of the power adapter according to the current sampling value when the power adapter enters a first charging mode, wherein,

when the output current of the power adapter is at a rising edge or a falling edge, the control unit shields the first capacitor bank, wherein the rising edge refers to a stage that the waveform of the output current is at a rising stage, and the falling edge refers to a stage that the waveform of the output current is at a falling stage;

when the output current of the power adapter is in a platform section, the control unit enables the first capacitor bank to work, and the platform section refers to a stage that the waveform of the output current is stable and unchangeable.

2. The power adapter as described in claim 1, wherein said first capacitor bank comprises a plurality of solid state capacitors connected in parallel and said second capacitor bank comprises a plurality of ceramic capacitors connected in parallel.

3. The power adapter according to claim 1, further comprising a selection switch, wherein one end of the selection switch is connected to one end of the first capacitor bank, the other end of the selection switch is grounded, a control end of the selection switch is connected to the control unit, and the other end of the first capacitor bank is connected to an output end of the second rectifying unit.

4. The power adapter of claim 3 wherein,

when the output current of the power adapter is at a rising edge or a falling edge, the control unit controls the selection switch to be switched off;

when the output current of the power adapter is in a platform section, the control unit controls the selection switch to be closed.

5. The power adapter as claimed in claim 3, wherein the selection switch is a MOS transistor.

6. The power adapter as claimed in any one of claims 1-5, wherein the control unit enables the first capacitor bank to operate when the power adapter enters a second charging mode, wherein a charging speed of the first charging mode is greater than a charging speed of the second charging mode.

7. The power adapter according to any one of claims 1-5, further comprising a first charging interface, the first charging interface being connected to the output terminal of the second rectifying unit, the first charging interface comprising a power line and a data line, the power line being used for charging a battery of a terminal, the data line being used for communicating with the terminal, the control unit being used for communicating with the terminal to determine a charging mode when the first charging interface is connected to a second charging interface of the terminal, wherein the charging mode comprises a first charging mode and a second charging mode.

8. The power adapter as claimed in claim 7, wherein when the power adapter enters the first charging mode, the power adapter applies the voltage of the third ripple waveform to the battery of the terminal through the second charging interface, wherein the second charging interface is connected to the battery.

9. An electrical charging system, comprising:

a terminal;

the power adapter of any one of claims 1-8, the power adapter to charge the terminal.

10. A charging method for a terminal, wherein the terminal is charged through a power adapter, a first capacitor bank and a second capacitor bank are connected to a secondary side of the power adapter, the charging method comprising the steps of:

performing primary rectification on input alternating current to output a voltage of a first ripple waveform;

modulating the voltage of the first ripple waveform by controlling a switching unit in the power adapter, and outputting the voltage of a second ripple waveform by transformation of a transformer;

performing secondary rectification on the voltage of the second ripple waveform to output a voltage of a third ripple waveform;

carrying out current sampling on the output after secondary rectification to obtain a current sampling value, and judging the output current of the power adapter according to the current sampling value when the power adapter enters a first charging mode;

when the output current of the power adapter is at a rising edge or a falling edge, shielding the first capacitor bank, wherein the rising edge refers to a phase that the waveform of the output current is at a rising stage, and the falling edge refers to a phase that the waveform of the output current is at a falling stage;

and when the output current of the power adapter is in a platform section, enabling the first capacitor bank to work, wherein the platform section refers to a stage that the waveform of the output current is stable and unchangeable.

11. The charging method for a terminal of claim 10, wherein the first capacitor bank comprises a plurality of solid state capacitors connected in parallel and the second capacitor bank comprises a plurality of ceramic capacitors connected in parallel.

12. The charging method for a terminal according to claim 10, wherein the power adapter further comprises a selection switch, one end of the selection switch is connected to the first capacitor bank, the other end of the selection switch is grounded, and a control terminal of the selection switch is connected to a control unit, wherein,

when the output current of the power adapter is at a rising edge or a falling edge, controlling the selection switch to be switched off;

and when the output current of the power adapter is in the platform section, controlling the selection switch to be closed.

13. A charging method for a terminal as claimed in any of claims 10 to 12, wherein the first bank of capacitors is enabled to operate when the power adapter enters a second charging mode, wherein the charging speed of the first charging mode is greater than the charging speed of the second charging mode.

14. A charging method for a terminal according to any of claims 10-12, wherein the power adapter further comprises a first charging interface comprising a power line for charging a battery of the terminal and a data line for communicating with the terminal, wherein the charging mode is determined by communicating with the terminal when the first charging interface is connected with a second charging interface of the terminal, the charging mode comprising a first charging mode and a second charging mode.

15. The charging method for the terminal according to claim 14, wherein when the power adapter enters the first charging mode, the power adapter applies the voltage of the third ripple waveform to a battery of the terminal through the second charging interface, wherein the second charging interface is connected to the battery.